Hey I know im late. Hope u know I have a 94 9c1 caprice with lt1. Im doing a opti and water pump and seal change out. When I got the opti off had oil coming out of it. So on the hole that u hook the opti on has oil coming out of it. Is this some that I can fix and if so how or is this a rebuild thing. I just the car drivable until I can afford a rebuild.
Most likely you have a bad seal on the timing chain cover. It may require you to pull the cover to replace it, but can't remember off the top of my head.
I own a '94 6spd and my water pump failed, causing the coolant to flood my optispark and rendering it useless. Take note: I upgraded the optispark with an improved "vented" version from the '95/'96 models. I also used high temp silicone and sealed the perimeter where the cap meets the body. I then snaked the vent line up into through the firewall and into the underside of the dashboard. 20 years later and she's still running like a Swiss watch! BTW, ingenious in it's design, the distributor was relocated down below the front of engine in order to lower the hood line to increase the coefficient of drag. Remember, this was pre individual coil overs.
Hey Rick, that seems like a good preventive measure to avoid some.of the common failure points of the system. Nice udea about running the vent line to dash area. Thanks for sharing the information👍.
I saw one guys solution to bad water pumps leaking on the Optispark . He threaded the weep hole on the water pump and installed a 45 degree elbow with a drain tube on it . That way , if ( when ) Your Water pump goes out , it won't leak all over the Optispark .
I am looking at the other side of the coin and I think the design was genius. Water pumps fail... When you have to replace/service the opti you replace the water pump as preventative maintenance and the engine doesn't experience a catasrophic failure. The LT1 was a great leap forward and I applaud the engineers for taking the chance and for GM to allow it. I'm not sure if we would have the LS without the LT1.
Good point Anthony, sometimes it's easy to forget that in engineering design, much thought is given to component replacement and billable hours for removal and replacement. If you consider each new piece of tech as a stepping stone to the next, it's easy to follow the progression of how engines and their individual components have evolved. Thanks for the comments👍
Please tell me how to " maintain" an Optispark I also have a '75 and a '68. It takes about 20 minutes to change the cap,rotor and wires .That's if I stop for a beer On the ,94 it took me 3 hrs and the OEM Opti with the Mitsubishi sensor was $500 I'm not ignorant about it. I just don't get the reasoning.And my Vettes could never be mistaken for an Impala
What I did on my 94 z28. First Gen opti. 3 holes on the bottom of the opti housing . I tapped the holes and added fittings the center hole I ran a line to air filter box drilled and placed A fitting there, Connected so that it pulls a slight vacuum. The other 2 I ran up and made a breather box. At the top of the opti where the wires go in I apoxyed it closed. Now I have no issues of purging the older opti. The ICM I removed it from the head and Extended the wiring and mounted it the wheel well to keep it cool.
That's a pretty ingenious solution. Like you said, keeps you from having to worry about moisture buildup, and ensuring the opti unit will hold up long term. Thanks for sharing👍.
After only about 35,000 miles the optispark on my always garaged 1994 LT1 Trans Am failed. It still ran in kind of a limp home mode. No local shops wanted to try and fix it....and they also claimed they didn't have OBT 1 analyzers. I made an educated guess and had a mechanic replace the optispark and that fixed the problem. My original optispark was very rusted. I no longer will drive my optispark Trans Am in the rain or if the streets are wet.
I hear ya, they can be problematic sometimes for the most random reasons, like if there's too much moisture or condensation in the air. If you own one long term, you just find the workarounds.
Very good system upgrade for it's time if you do the research of how it actually works it will amaze you in comparison to the H.E.I. ignition system of the time, the version2 of it is the most reliable due to being vacuum cleaned from filtered air, this system could keep timing within only 1° of perfect timing which is very impressive compared to other units of its time!!
Thanks for sharing the detailed information. I was always under the impression this system had many strengths, it was always just the odd placement under the water pump that thew me off.
96-97 have the vented optispark which is a much better design. My 97 trans am still has the factory opti at 210 k and I just replaced the cap and rotor as a safety measure when I had the water pump off! The inner parts where clean of water and oil and I was impress lol
Thats a pretty impressive testament to the durability of the later units. Then of course they ditched it company wide by 1998. Makes perfect sense in the car manufacturers world. 😁
I’m looking at a 1994 Camaro that has an LT1. I’m doing all my research now and other than the opti-spark they’re damn good engines. Thanks for the education.
Over 170k miles on the original Optispark in my 96 Buick Roadmaster sedan. I'm gonna rebuild it soon when I do the timing chain and seals. But it still runs great
This is the far most best video information on the Optispark in the 90’s c4 corvette, great details and explanation that was involved! I just bought a C4 Corvette. I have a C-5 and love it! But not familiar with the OPTi spark, I’ve been trying to start mitt with no success it was running and just cut off like a switch. Wasn’t sure if it was a fuel related issue even though it had low fuel added 8 gallons still no start. So this video gives me a little insight on what to do. Just want to say thank you!
I have a 93 corvette with 23,000 miles.Thing just quit running the other day.Needed a new optispark.Had a dealership change it out with a new opti and waterpump.Not a cheap fix.Good luck.
Kenneth, glad you enjoyed it and found it helpful. Congratulations on your new to you Corvette purchase. You have years of fun and great memories with it👍.
The Optispark is at least twice as reliable as the HEI system it replaced. never had to change an optispark on our LT in the '94 Caprice. It uses the updated V2 Optispark which uses engine vacuum to draw clean filtered air through it. If you want the difference between V1 and V2 is the Opti unit itself and the timing chain cover. V2 uses a much larger hole in the timing chain cover. In the Caprice I believe '94 was first year for V2 of the Opti. Its been wet more than once. the water pump has drenched it at least once. a garage that figured the opti was at fault because it was wet ( actually from the Throttle body ) and wwas actually spraying water on the front of the engine for some unexplicable reason. The Original Opti is still on the car. As for the opti, it is driven straight off the cam. it has to turn at camshaft speed. the spline drive for the water pump is about 11:1 ratio ( I did do the count years back but I just forget ).
Good info, thanks for sharing👍. They certainly are a neat piece of engineering, and dead reliable with consistent use and maintenance. I think they get a bad rap due to the difficulty in accessing them, especially on the Corvettes.
Everyone talks about this “problem” yet my 1993 camaro still had the original factory opti spark at 150,000 miles. Vehicle was still running fine when I decided to replace it while doing plugs and wires that were 15 years old and just decided to replace it all. J/s
Yep, we've see quite a few different experiences with the Optispark system in the comments. The common thread seems to be the garage kept cars, or the ones kept away from excessive moisture hold up pretty well long term. Thanks for sharing your experience, sounds like it's been a good car for you👍.
Another annoyance I have with GM, they already had direct coil ignition for a good 10 years, yet they went through the trouble to make this difficult to service and failure prone system, and for a car with little space to work with. And they knew it. It's not like it was done this way to save money either, it was just someone being clever and the customers and dealers having to deal with the problems after. At least it helps keep the sales price of this series vettes down and let the aftermarket make some money coming up with ways to improve the system.
Yea, I often wonder if the Corvette, Cadillac, and Lincoln engineers come up with crazy stuff just to say they did it and see if it will end up working. Don't even get me talking about the starter and coil pack setup on the LT5's in the ZR-1's😂
@@VetteSource Toyota's been hiding starters in their engines for a while. Imagine the fun of having to remove the intake just to change one! I saw pics of another with the starter being inside the bellhousing, meaning transmission removal just for a starter change! And here I thought changing the spark plugs on a 1975 corvette was fun..
I know what you mean. I had a great little Nissan pickup years ago that was great a runner and always dependable. However it was never any fun to work on as it seemed the engine compartments were designed for people with much smaller hands than mine.
That's the best thing in the world for them, machines need to keep moving or they tend to go south. I think that probably applies to people as well😂. Thanks for the feedback, appreciate it👍
@@VetteSource Check out Torqhead 24x coil packs that do away with the distributor.411 PCM plug and play is also an upgrade.It will allow for more defined tuning for OBD1 LT1s.
I tapped the weep hole and installed a hose barb with a rubber line going past the Optispark and down between the cross member so if it leaks it will on the street and not on the unit itself.
You said you were certain the ECM was good because you checked it with the scan tool. What did you mean by that? What scan tool can check the ECM? Do you have a video on that? Thanks.
I use a Snap-On MT2500. It's an older scan tool used for the OBDI and early OBDII systems. You cam find them for sale on eBay or the other classifieds sites.
I have a question. I let my car set the last two months. 96 Chevy caprice. LTL motor....November and December. During that time we had a ice storm in my city. I went to jump back in it and it's rough idle and wants to cut off when at a light and smell a little gas. It doesn't run strong like it did before the below 0 temps hit my city last month. I changed fuel filter first before changing spark plugs and opti spark. What you suggest I should look for?
It's possible you have some residual moisture built up in the optispark or at the plug wire connections after the ice storm. As silly as it sounds, try applying some heat with a hair dryer or heat gun(low setting) around the optispark cap at the wire terminals. You'd be surprised how quickly that will remove moisture. Let me know how it works out👍.
Hey Lewis, it possible you have an intake manifold to head leak at either the front or rear intake/head seal. I would also take the time to do a compression check to make sure you don't have a failing head gasket.
When you put the new distributor back in, how does it key so you have the same timing as you had when you pulled it? It didn't look like the stub gear had a tab on it.
Most likely it's a failure of the oil seal that is located where the distributor drive gear comes through the timing chain cover from the front of the camshaft. If you have it dismantled already, you can easily check it for oil seepage.
I have a 1992 corvette with the lt1 i drove it today it died on me twice started back up both times i pulled the codes and i got code 16 low resolution. Does that mean i need a new optispark?
With a code 16, it's very possible the optispark is failing or is about to. I would recommend performing the troubleshooting steps on the complete circuit to verify before tearing it down. Let me know how it turns out👍
94 FB LT1 Automatic 78k miles; hot, stumbles/chuggles/misfires on med hard accel. Clears out and then accels OK. Suspect coil because it seems OK cold. If not coil, should I try just cap and rotor since that's what corrodes? Why even take off the distributor?
Definitely sounds ignition related. I always recommend starting with the easy to access components like the LT1 coil and working your way backwards. Usually if there are signs of moisture in the cap/rotor area, it's best to go ahead and change the distributor assembly because moisture has probably made its way into there as well.
My introduction to the C4 is a 1990 ZR-1, never had the privilege to work on a optispark. Looks like a beast. Did the LT-4 have this system? Good info, always interesting videos. 👍👍🏁🏁
Thanks Michael, I'm having a good time sharing the knowledge. The LT-4 has the optispark as well, however they had refined it by that point to make it a little less prone to moisture contamination. How is your ZR-1 coming along?
This was a really good explanation of the optispark system. But on my 92 vette, I DO have spark, but it cuts out whenever the engine gets warm. So I am wondering if it is the opti, or maybe it's the coil or the O2 sensors. Since the car starts and runs good up until it gets to operating temp, is it likely the optispark, or maybe something else?
I wouldn't suspect the O2 sensors, since they can be completely inoperative and the engine will still chug along. Something in the system is cutting out when the engine goes closed loop. Since the fuel injector drivers are driven by the ECM, they will tend to either work or not work. I would take a closer look at the ignition system, starting at the plug wires to see if you're losing spark once you reach operating temperature. From there you can backtrack to the optispark to see what's going on.
@@VetteSource I suspect there is something in your comment. I will check it out. But what I also wonder is, is there any tie-in between temperature and the opti? In other words, is there something about the way the opti operates that could make it shut the engine down at higher temps?
It's possible that the optical sensor or one the internal components is failing once it gets hot, but there's no way to tell without a visual inspection once it's all torn down. Checking from the plug wires going back will help you identify if there is anything else in the circuit causing problems before you have to dismantle the optispark.
I'm fixing to change a cam on my 97 lt. Is there a way to know when it's top dead center when taking the opti off? Or is that even important to try to do?
Easiest way is just pull the #1 plug, and manually rotate the engine until you reach TDC #1. Once you have the timing chain cover off, you will see the alignment marks on the timing and crank gear. Install the new cam using the same alignment.
I’m having problems with mine nobody can figure out. So it likes to stall and completely not start at all. It was a little sluggish when I pressed the gas and it often stalls if I stop at a light or stop signs. I bought it as a 19 year old and it had no signs of issues. Now they all came and I’m being hated on by my entire family so it needs fixed 🤷♂️ I hope you can maybe have a suggestion of what the problem may be
Sounds like you will need to get some of the basic checks out of the way first. My first thought would be to make sure you don't have bad fuel or fuel filter. Next, check to make sure you don't have any airflow restrictions into the throttle body, then check the fuel pressure at the fuel rail with an appropriate gauge. If those check out fine, then you will need to check for correct spark and injector pulse. Let me know how it turns out, and don't worry about everyone hating on you about what car you choose to drive. It's a Corvette, and many people won't understand😁.
Hi, I have a 1990 corvette. It runs great when driving but when I am a complete stop smoke starts coming from the right portion of the engine. I took it to a mechanic and he says the engine needs a total rebuild. Have you heard of the issue I’m experiencing?
Hey Scott, frankly it seems a bit premature for a mechanic to diagnose a smoking engine as needing a complete engine rebuild without a thorough inspection detailing the findings. A leaking intake manifold, valve cover, or oil pan gasket can all cause the same symptoms you are describing. My recommendation is to solicite opinions from multiple shops to get a sense of what might be going on. I like to look at Google reviews of places I am thinking of doing business with to get an idea of how they conduct themselves. Let me know how it turns out and if you need any further information.
Definitely could be an optispark issue, but I'm afraid you'll have to dig into it in real time to figure out what's going on. I would start with the coil mounted at the front of the passenger side head to check for bad/loose connection and proper operation once it has stopped running with a spark checker. If that checks out ok, I would start looking closer at the optispark itself. Let me know how it's going👍.
Generally speaking, I usually try and stick with OEM on the Corvette stuff. However, I'm not sure that GM is still offering an optispark replacement, so you're left to choose from the aftermarket suppliers. I don't have a personal preference eight now, but looking at the catalog offerings there aren't many options available. I would say stay away from the cheaper units, and take a closer look at the Cardone piece and see what kins.of reviews it has. Let me know if you need any more recommendations.
Hey Bill, other than water pump seals if you elect to replace the pump, everything on the optispark is pretty much self contained and sealed up like the older distributors so you shouldn't need to purchase anything extra.
Good video, a couple questions I want to throw out for anyone’s opinion. I have a 95, only 49,000 but expect some day I will have to deal with the dreaded optispark. When your opti dies, how many consider replacing with a superior system versus a “standard” optispark? Also, since the water pump comes out, Great idea to replace it, anyone consider replacing with an electric? Again, since the water system is drained, consider installing a dual-core radiator?
Thanks for the feedback, glad you enjoyed it. Personally I prefer stock installations on my replacement parts unless I am doing a hot rod build, plus the OEM usually is a better quality than most aftermarket pieces. However, somebody that has gone that route may have more experience than me with those types of installs and can chime in.
I need some help and advice.I fixed the ignition problem?. Water pump and so on. The 94 runs great. Now when it comes up to temp the fans turn on then 5 seconds later it stalls. Crank no start.....again
Wow, that is an unusual problem. Under normal operation, the fan circuit doesn't have anything to do with the ignition system. I'm afraid this will require some electrical troubleshooting to figure out what is going on. Does your engine harness look like it has any previous repairs or splices? After you get the no start condition, how long does it take before it wants to crank back up again?
Usually a couple hrs. Maybe overbite. When I noticed what was happening I cranked it and let it run. At temp it cut off. I can't remember is the fans cut off too like a complete power failure I'll look next time. Harnesses are fine
Ok, it's possible you have a bad ground connection. I would check those first. If those check out, I would start looking at the ECM and harness connectors.
The only common connection location is the ECM. All roads lead to the company I researched that sells them preprogrammed You just provide your VIN. Plug and play
Good info, thanks for sharing👍. Quite a few of the aftermarket suppliers have come up with optispark alternatives. I don't think I've heard of this system. I'll have to look into it further.
@@VetteSource I've had it in my 94 Z28 for 2 years now and it works great. It's just as easy to install as it is to replace the optispark. I got to know Paul the owner/designer very well and he's glad to answer any questions you may have. My optispark died on the road, my water pump was weeping slightly and it wipped out the bearing causing it to seize and the spline drive shaft broke off in the cam sprocket with 87,000 miles on the car. The best thing about Torqhead is it's plug and play, no wire splicing. I even brought a spare PCM from him for only $350.00. All the other sensors and coils are AC Delco off the shelf parts. Now I have an OB11 computer and my scan tool gives me so much information.
unfortunately the early units are prone to internal wear of the crank sensor and even with cleaning still don't want to function correctly. Might be easier to replace at this point rather than spend extra time on troubleshooting. Thanks for watching👍
Hey Roberto, definitely want to change out for new seals as they tend to dry out and shrink with time. I believe the new units will come with replacement seals
I've heard about it from a few different sources, but haven't ever been able to personally test it for durability and compatibility. Let me know if you have the information on it, and I will give it a closer look.
@@VetteSource looks like it's really iffy checking the vette forums, some opt to keep the opti attached but use the ls wires and have the voltage isolated to the black box controller which makes the system think the opti is good albeit its just not on, and some report the car is fine when you take it out and just use the black box, i think to stay safe i would do the first option albeit you still have to change the opti if it dies, you have a gained benefit of being able to control spark and the problem of the opti dying from water, i think the best more bulletproof option is the ventilated opti though which seemed to fix the problem and no ecu problems. 🤷♀️ it really astounds and amuses me the way people fix problems in the most ingenious ways with these cars 😂
Honestly it sounds kind of like a Rube Goldberg Machine. Not sure if you've heard of them, but it's essentially an overly complicated way to solve a minor problem. I've seen quite a few of these "workarounds" on newer cars when the electrical issues couldn't be figured out.
Optispark's are dead nuts reliable and typically last well over 200,000 miles without any issues. My last optispark was changed out at 300,000 miles. Everyone wrongly assumes that the optispark is the problem when it is typically the spark plug wires that need replacing. The ignorance and propaganda about these LT1 engines and the optispark allows me to pick them up used for song. I mean, come on, do you really think you'd get 2, 3 or 4 bad optispark's in a row? Lol.
I think you're right that under normal consistent usage these things will are pretty reliable. However, Corvettes are often bought as "toys" and don't see daily use. That's when most of the problems start to occur with water pump seals and gaskets drying out and moisture accumulation. Thanks for watching👍
Thanks for sharing this video. I subscribed. I washed my engine bay on my 94 Z28 and it ran like crap. I let it dry after the engine was at operating temps for a few hours. Still miss fires. How long do you think it takes before all the moisture evaporates??? if it does??
No problem, thanks for the sub. The 94 should have the moisture vent built into it, but like you can see in the video sometimes that crusty material will collect inside the cap causing driveability problems. I've seen people use heat guns and even park the car on a hot street surface during the summer in an effort to evaporate the residual moisture. At the worst it doesn't do anything, but at least you can give it a shot before having to take the water pump out to get at it.
@@VetteSource Thanks for your reply. I'm hoping the moisture will evaporate by morning. We will see. It ran perfectly before I pressure washed the engine. And I was aware of not spraying the water pump area.... opti spark. I thought the vent on the opti spark was on the 96-97 LT1??
It may have been 95 and later LT's, I may be misremembering. Also, I should have said hair dryer and not heat gun, that would result in a few melted pieces😁
My license is suspended for medical but I dream of getting my license back and getting a C4 Vette. If I get to live my dream one day, do you recommend the L98 vettes or the LT1 vettes? Is the Lt1 worth some of the headaches?
Both engines have their individual strengths and weaknesses, but for overall day to day enjoyment, I would look for a nicely kept 95-96 C4. They are well built, awesome road cars, and quite comfortable serving as a daily driver. The best part is that they are seriously undervalued right now, and can be had for a song compared to how expensive they were when new.
@@VetteSource thanks so much for replying. I hear on reddit all the time that for the price of a well sorted lt1 6 speed C4 you may as well just pony for a C5. Any truth to that? You seem to know your shit!
@@Jason-fp7vi those words are usually spoken by people who have never driven a C4😂. While C5's are great cars, I prefer the driving feedback you get from a C4 vs the C5. Plus the electronics are becoming problematic on the C5's. They have a high failure rate of things like the EBCM and other modules and wiring that can be costly and time consuming to repair.
Distributor cap probably isn't going to do it. I would start by checking for power to the distributor first, and if that checks out, I would take a look at the ignition module first. Oddly enough, a bad rotor can also cause a no start condition. Let me know how it turns out👍
Hey man. I love your videos. I am on the lookout for a C4 LT4. Would you take a LT4 on long roadtrips where the car sits outside in the rain at night and drives in any sort of conditions in spring, summer and fall time? The optispark is good as long as you dont get it wet from underneath like a carwash or a flooded road for example? Are there parts available for the LT4?
Max, glad your enjoying the videos, appreciate the feedback👍. The later C4's are definitely very capable daily drivers in all types of weather and driving conditions. Like you said, avoid the carwashes and flooded roads and you should be fine. In fact the Aqua LT4 youve seen here in the channel gets parked in the driveway and driven as often as possible, regardless of the weather conditions.
They started out being rather expensive, and are still a bit more expensive than the HEI, but several aftermarket suppliers have stepped up to improve the design to ensure reliability. Thanks for the comment👍
Please take a look at my video. 95 impala ss bad misfire only on pass side, driver side no problem. took pass head of to check for stuck valves no problem there. plugs on pass side swapped from drivers side didn't fix it. I'm lost on this one unless there is a bad injectors (all 8 have good 12 volts and good ground) any suggestions would be appreciated. and yes removed the Opti to look for problem under the, cap on the pass side clean.??
Dantae, looking at the video it looks like you are going to have to dig a little deeper into the fuel and ignition system to find your problem. I would start by disconnecting your fuel injectors and spark plugs wires one by one on the passenger side while its running to see if you get any change in the way it runs. That way you can isolate which cylinder is having the problem and go from there. Let me know how that goes.
After watching ur video I'm not going to send the ECU off to get checked, I also have a 1993 corvette and it's no start, no spark, everything else was checked and changed I really didn't want to go through all of this but nothing else I did or changed worked so I guess I'm doing the opti spark 😡😡😡😡
@@VetteSource No cambie el Optispark pero ya lo solucione el problema era un cable que estaba desconectado del distribuidor pero igual muchísimas Grasias seguiré mirando sus videos
@@VetteSource Disculpa por tanta pregunta amigo , pero me podrías decir cómo purgarlo . Ósea mi Corvette se le sube la temperatura hasta 235 y después prende el primer abanico , me dijeron que lo purgara para sacarle todo el aire al sistema pero no se como hacerlo ,si me pudieras dar algunos tips te lo agradecería muchísimo de antemano muchas Grasias .
How is it a problem takes a lot of miles to go bad it's not a flaw on a normal motor you would have put several caps wires and rotor button stuff last close to a 100 thousand miles pretty awesome set up
You're correct, it's not a bad setup However, I think what I was referencing was the inherent difficulty in accessing and changing the unit out versus a good old fashioned cap and rotor. That along with the higher cost of the replacement parts has turned people off to the system.
🤣 you are VERY correct. There isn't much room to work in there with the appropriate tools to get that thing off of the hub. However, did you notice the 3 bolts that separate the balancer from the hub shaft? They designed it with a built in hack so you could get the balancer off in stages rather than trying to get everything off at once.
Gotcha, if you have confirmed proper fuel pressure at the rail of 42-46 PSI and spark at the cylinders I would guess your having a fuel injector pulse issue during cranking which may end up being a ECM issue.
Great, that's good news. Glad to hear you got it back on the road. I'll be tearing into the 97 Aqua LT4 soon. The water pump just started leaking the other day so I'll be tearing it down to replace everything.
Hey Javier, funny thing is that most of the car this engine was pulled from burned to the ground due to a battery charger left on it for too long. The leaking oil was the least of its problems😁. Thanks for the comments.
Yea, definitely a potential failure point, but if kept up with maintenance wise the later C4 optisparks last for many years. My 2 96 LT4 Corvettes, one with 23K miles and the other with 135K are both running their original systems.
@@VetteSource no not any that im vocal on. Just found it funny we sound so similar n i have n lt1 im working on so it felt like i had blacked out n worked on my car n someone else taped it haha
SYS is a message generated by the BCM alerting you to a trouble code stored or something else wrong within the data line circuit. It will even flash "SYS" if you have a low battery voltage condition.
👉Nobody thought to put a bag or a rubber boot over this thing to keep moisture out? I had a brand new 96 back then, and if I left it outside, which I did, and if it rained that week, it didn't want to start by the weekend.. 😭
Amazingly, this car ran strong for well over 100,000 miles before the previous owner burned it to the ground in his driveway after leaving a battery charger hooked up to it for too long. Of course, maybe the oil leaks all over the front of the distributor helped keep some of the moisture out😁.
This was a motor from a burned salvage car that I dismantled for parts. Not much reason to clean it up until it gets freshened up to install in another car. Thanks for the feedback👍.
I will NEVER buy another Vette with that STUPID OPTISPARK!!!!! My 94 is awesome.....when it runs. I've thrown enough money at it to buy another one. From dream car to nightmare. They say the LT1 is dependable. NOT
Hey Paul, I understand your frustration. Sometimes when you have an optispark failure, it can be a challenge to find quality components or qualified technicians to make it work correctly again. Hope it works out for you. The 94's are great cars.
Be sure to check out my other videos for more cool Corvette How To Videos -
th-cam.com/play/PLAM-V1w3acpivjkfJyWbE99E1FcOaXKys.html
Hey I know im late. Hope u know I have a 94 9c1 caprice with lt1. Im doing a opti and water pump and seal change out. When I got the opti off had oil coming out of it. So on the hole that u hook the opti on has oil coming out of it. Is this some that I can fix and if so how or is this a rebuild thing. I just the car drivable until I can afford a rebuild.
Hey Jay, you're referring to the cam gear coming out of the timing chain cover?
@@VetteSource yes right behind the gear that powers the optispark
Most likely you have a bad seal on the timing chain cover. It may require you to pull the cover to replace it, but can't remember off the top of my head.
@@VetteSource cool thanks
I own a '94 6spd and my water pump failed, causing the coolant to flood my optispark and rendering it useless. Take note: I upgraded the optispark with an improved "vented" version from the '95/'96 models. I also used high temp silicone and sealed the perimeter where the cap meets the body. I then snaked the vent line up into through the firewall and into the underside of the dashboard.
20 years later and she's still running like a Swiss watch!
BTW, ingenious in it's design, the distributor was relocated down below the front of engine in order to lower the hood line to increase the coefficient of drag. Remember, this was pre individual coil overs.
Hey Rick, that seems like a good preventive measure to avoid some.of the common failure points of the system. Nice udea about running the vent line to dash area. Thanks for sharing the information👍.
I saw one guys solution to bad water pumps leaking on the Optispark .
He threaded the weep hole on the water pump and installed a 45 degree elbow with a drain tube on it . That way , if ( when ) Your Water pump goes out , it won't leak all over the Optispark .
That's using your noggin. Good way to head off potential future issues without having to tear it down multiple times. Thanks for the comments👍.
I did that 3 years ago, something GM should have done for less than a buck.
I'm about to replace the water pump on the Aqua LT4 and Black LT1. I think we'll try this out and see how it works.
I am looking at the other side of the coin and I think the design was genius. Water pumps fail... When you have to replace/service the opti you replace the water pump as preventative maintenance and the engine doesn't experience a catasrophic failure. The LT1 was a great leap forward and I applaud the engineers for taking the chance and for GM to allow it. I'm not sure if we would have the LS without the LT1.
Good point Anthony, sometimes it's easy to forget that in engineering design, much thought is given to component replacement and billable hours for removal and replacement. If you consider each new piece of tech as a stepping stone to the next, it's easy to follow the progression of how engines and their individual components have evolved. Thanks for the comments👍
Please tell me how to " maintain" an Optispark
I also have a '75 and a '68.
It takes about 20 minutes to change the cap,rotor and wires .That's if I stop for a beer
On the ,94 it took me 3 hrs and the OEM Opti with the Mitsubishi sensor was $500
I'm not ignorant about it.
I just don't get the reasoning.And my Vettes could never be mistaken for an Impala
What I did on my 94 z28. First Gen opti. 3 holes on the bottom of the opti housing . I tapped the holes and added fittings the center hole I ran a line to air filter box drilled and placed
A fitting there, Connected so that it pulls a slight vacuum. The other 2 I ran up and made a breather box. At the top of the opti where the wires go in I apoxyed it closed.
Now I have no issues of purging the older opti.
The ICM I removed it from the head and Extended the wiring and mounted it the wheel well to keep it cool.
That's a pretty ingenious solution. Like you said, keeps you from having to worry about moisture buildup, and ensuring the opti unit will hold up long term. Thanks for sharing👍.
After only about 35,000 miles the optispark on my always garaged 1994 LT1 Trans Am failed. It still ran in kind of a limp home mode. No local shops wanted to try and fix it....and they also claimed they didn't have OBT 1 analyzers. I made an educated guess and had a mechanic replace the optispark and that fixed the problem. My original optispark was very rusted. I no longer will drive my optispark Trans Am in the rain or if the streets are wet.
I hear ya, they can be problematic sometimes for the most random reasons, like if there's too much moisture or condensation in the air. If you own one long term, you just find the workarounds.
Very good system upgrade for it's time if you do the research of how it actually works it will amaze you in comparison to the H.E.I. ignition system of the time, the version2 of it is the most reliable due to being vacuum cleaned from filtered air, this system could keep timing within only 1° of perfect timing which is very impressive compared to other units of its time!!
Thanks for sharing the detailed information. I was always under the impression this system had many strengths, it was always just the odd placement under the water pump that thew me off.
I agree and mine on my 1993 was the original one until this week when I changed it while doing other thing. It still worked fine though.
That is 100% correct, only distributor that had 360 degrees of timing, the later ls engines only had 54!
96-97 have the vented optispark which is a much better design. My 97 trans am still has the factory opti at 210 k and I just replaced the cap and rotor as a safety measure when I had the water pump off! The inner parts where clean of water and oil and I was impress lol
Thats a pretty impressive testament to the durability of the later units. Then of course they ditched it company wide by 1998. Makes perfect sense in the car manufacturers world. 😁
I’m looking at a 1994 Camaro that has an LT1. I’m doing all my research now and other than the opti-spark they’re damn good engines.
Thanks for the education.
Cheddarman, glad to be of help👍. You'll have loads of fun with an LT-1. They have great power and quite dependable with routine maintenance.
Nice elaborate breakdown on the 5.7 litre LT1
Thanks Daniel, appreciate it👍
Over 170k miles on the original Optispark in my 96 Buick Roadmaster sedan. I'm gonna rebuild it soon when I do the timing chain and seals. But it still runs great
Definitely, I prefer a rebuilt factory unit over the aftermarket myself as well.
learned a ton about the LT1, thank you for sharing your time and knowledge
No problem. Glad to do it👍
This is the far most best video information on the Optispark in the 90’s c4 corvette, great details and explanation that was involved! I just bought a C4 Corvette. I have a C-5 and love it! But not familiar with the OPTi spark, I’ve been trying to start mitt with no success it was running and just cut off like a switch. Wasn’t sure if it was a fuel related issue even though it had low fuel added 8 gallons still no start. So this video gives me a little insight on what to do. Just want to say thank you!
I have a 93 corvette with 23,000 miles.Thing just quit running the other day.Needed a new optispark.Had a dealership change it out with a new opti and waterpump.Not a cheap fix.Good luck.
Kenneth, glad you enjoyed it and found it helpful. Congratulations on your new to you Corvette purchase. You have years of fun and great memories with it👍.
Wow. You made a perfect video with both Detail and explaining. I have a GTA 350 TPI. My first 350.
Thanks for the feedback👍. Sounds like a great car. Plenty of power with the TPI 350 for stoplight to stoplight fun.
The Optispark is at least twice as reliable as the HEI system it replaced. never had to change an optispark on our LT in the '94 Caprice. It uses the updated V2 Optispark which uses engine vacuum to draw clean filtered air through it. If you want the difference between V1 and V2 is the Opti unit itself and the timing chain cover. V2 uses a much larger hole in the timing chain cover. In the Caprice I believe '94 was first year for V2 of the Opti. Its been wet more than once. the water pump has drenched it at least once. a garage that figured the opti was at fault because it was wet ( actually from the Throttle body ) and wwas actually spraying water on the front of the engine for some unexplicable reason. The Original Opti is still on the car.
As for the opti, it is driven straight off the cam. it has to turn at camshaft speed. the spline drive for the water pump is about 11:1 ratio ( I did do the count years back but I just forget ).
Good info, thanks for sharing👍. They certainly are a neat piece of engineering, and dead reliable with consistent use and maintenance. I think they get a bad rap due to the difficulty in accessing them, especially on the Corvettes.
Not any more fragile than an old HEI distributor. As long as you didn't do any damage to the distributor cap you should be fine. 👍
Everyone talks about this “problem” yet my 1993 camaro still had the original factory opti spark at 150,000 miles. Vehicle was still running fine when I decided to replace it while doing plugs and wires that were 15 years old and just decided to replace it all. J/s
Yep, we've see quite a few different experiences with the Optispark system in the comments. The common thread seems to be the garage kept cars, or the ones kept away from excessive moisture hold up pretty well long term. Thanks for sharing your experience, sounds like it's been a good car for you👍.
Another annoyance I have with GM, they already had direct coil ignition for a good 10 years, yet they went through the trouble to make this difficult to service and failure prone system, and for a car with little space to work with. And they knew it. It's not like it was done this way to save money either, it was just someone being clever and the customers and dealers having to deal with the problems after. At least it helps keep the sales price of this series vettes down and let the aftermarket make some money coming up with ways to improve the system.
Yea, I often wonder if the Corvette, Cadillac, and Lincoln engineers come up with crazy stuff just to say they did it and see if it will end up working. Don't even get me talking about the starter and coil pack setup on the LT5's in the ZR-1's😂
@@VetteSource Toyota's been hiding starters in their engines for a while. Imagine the fun of having to remove the intake just to change one! I saw pics of another with the starter being inside the bellhousing, meaning transmission removal just for a starter change! And here I thought changing the spark plugs on a 1975 corvette was fun..
I know what you mean. I had a great little Nissan pickup years ago that was great a runner and always dependable. However it was never any fun to work on as it seemed the engine compartments were designed for people with much smaller hands than mine.
Can you review the more difficult ground points to access and clean? 106 and 107. Mention what each ground handles please
Sure, I'll put that on my video production schedule👍.
awesome videos,,,i would love an upgrade,,,mine runs well,,,always keep it from the wet,,keep covered,,no rain,,,no sitting for extended times
That's the best thing in the world for them, machines need to keep moving or they tend to go south. I think that probably applies to people as well😂. Thanks for the feedback, appreciate it👍
Do yourself a favor and buy the MSD opti-spark.Much more reliable and no moisture problems.Stay away from the cheaper Accel version,it's junk.
Yep, ive seen that the Accel units tend to be problematic.
@@VetteSource Check out Torqhead 24x coil packs that do away with the distributor.411 PCM plug and play is also an upgrade.It will allow for more defined tuning for OBD1 LT1s.
Cool, I'll check it out in a few👍.
About to change the intake manifold gaskets on my 96, should be a fun learning experience! Lol
Remember slow and steady wins the race, and tons of pictures with the smart phone camera. Best visual aid you'll ever get👍
I tapped the weep hole and installed a hose barb with a rubber line going past the Optispark and down between the cross member so if it leaks it will on the street and not on the unit itself.
Great idea, thanks for sharing👍
You said you were certain the ECM was good because you checked it with the scan tool. What did you mean by that? What scan tool can check the ECM? Do you have a video on that? Thanks.
I use a Snap-On MT2500. It's an older scan tool used for the OBDI and early OBDII systems. You cam find them for sale on eBay or the other classifieds sites.
Thanks for the educating, learned a lot about the optispark.
No problem, glad to do it👍.
I have a question. I let my car set the last two months. 96 Chevy caprice. LTL motor....November and December. During that time we had a ice storm in my city. I went to jump back in it and it's rough idle and wants to cut off when at a light and smell a little gas. It doesn't run strong like it did before the below 0 temps hit my city last month. I changed fuel filter first before changing spark plugs and opti spark. What you suggest I should look for?
It's possible you have some residual moisture built up in the optispark or at the plug wire connections after the ice storm. As silly as it sounds, try applying some heat with a hair dryer or heat gun(low setting) around the optispark cap at the wire terminals. You'd be surprised how quickly that will remove moisture. Let me know how it works out👍.
@@VetteSource ok thanks. Gonna try it
Great video i have a 1993 camaro with a LT1 what would go wrong with the intake to dump antifreeze into the oil
Hey Lewis, it possible you have an intake manifold to head leak at either the front or rear intake/head seal. I would also take the time to do a compression check to make sure you don't have a failing head gasket.
When you put the new distributor back in, how does it key so you have the same timing as you had when you pulled it? It didn't look like the stub gear had a tab on it.
it will be keyed to install a certain direction, so you just need to line up the keyway
I have oil inside the optispark, do you know how It could be possible?
Most likely it's a failure of the oil seal that is located where the distributor drive gear comes through the timing chain cover from the front of the camshaft. If you have it dismantled already, you can easily check it for oil seepage.
I have a 1992 corvette with the lt1 i drove it today it died on me twice started back up both times i pulled the codes and i got code 16 low resolution. Does that mean i need a new optispark?
With a code 16, it's very possible the optispark is failing or is about to. I would recommend performing the troubleshooting steps on the complete circuit to verify before tearing it down. Let me know how it turns out👍
94 FB LT1 Automatic 78k miles; hot, stumbles/chuggles/misfires on med hard accel. Clears out and then accels OK. Suspect coil because it seems OK cold. If not coil, should I try just cap and rotor since that's what corrodes? Why even take off the distributor?
Definitely sounds ignition related. I always recommend starting with the easy to access components like the LT1 coil and working your way backwards. Usually if there are signs of moisture in the cap/rotor area, it's best to go ahead and change the distributor assembly because moisture has probably made its way into there as well.
Thanks. Great video. I was wondering if we can use
MSD distributor aftermarket ? Which one is more reliable ?
Hey Ali Reza, glad you enjoyed it. I've heard good things about the MSD unit.sl I would t hesitate in making the investment if I needed to replace it.
My introduction to the C4 is a 1990 ZR-1, never had the privilege to work on a optispark. Looks like a beast. Did the LT-4 have this system?
Good info, always interesting videos. 👍👍🏁🏁
Thanks Michael, I'm having a good time sharing the knowledge. The LT-4 has the optispark as well, however they had refined it by that point to make it a little less prone to moisture contamination. How is your ZR-1 coming along?
This was a really good explanation of the optispark system. But on my 92 vette, I DO have spark, but it cuts out whenever the engine gets warm. So I am wondering if it is the opti, or maybe it's the coil or the O2 sensors. Since the car starts and runs good up until it gets to operating temp, is it likely the optispark, or maybe something else?
I wouldn't suspect the O2 sensors, since they can be completely inoperative and the engine will still chug along. Something in the system is cutting out when the engine goes closed loop. Since the fuel injector drivers are driven by the ECM, they will tend to either work or not work. I would take a closer look at the ignition system, starting at the plug wires to see if you're losing spark once you reach operating temperature. From there you can backtrack to the optispark to see what's going on.
@@VetteSource I suspect there is something in your comment. I will check it out. But what I also wonder is, is there any tie-in between temperature and the opti? In other words, is there something about the way the opti operates that could make it shut the engine down at higher temps?
It's possible that the optical sensor or one the internal components is failing once it gets hot, but there's no way to tell without a visual inspection once it's all torn down. Checking from the plug wires going back will help you identify if there is anything else in the circuit causing problems before you have to dismantle the optispark.
That usually happens when your Ignition Control Module goes bad not the opti-spark. It sits right near the coil.
I'm fixing to change a cam on my 97 lt. Is there a way to know when it's top dead center when taking the opti off? Or is that even important to try to do?
Easiest way is just pull the #1 plug, and manually rotate the engine until you reach TDC #1. Once you have the timing chain cover off, you will see the alignment marks on the timing and crank gear. Install the new cam using the same alignment.
Great video much appreciated
No problem, glad you enjoyed it👍
I’m having problems with mine nobody can figure out. So it likes to stall and completely not start at all. It was a little sluggish when I pressed the gas and it often stalls if I stop at a light or stop signs. I bought it as a 19 year old and it had no signs of issues. Now they all came and I’m being hated on by my entire family so it needs fixed 🤷♂️ I hope you can maybe have a suggestion of what the problem may be
Sounds like you will need to get some of the basic checks out of the way first. My first thought would be to make sure you don't have bad fuel or fuel filter. Next, check to make sure you don't have any airflow restrictions into the throttle body, then check the fuel pressure at the fuel rail with an appropriate gauge. If those check out fine, then you will need to check for correct spark and injector pulse. Let me know how it turns out, and don't worry about everyone hating on you about what car you choose to drive. It's a Corvette, and many people won't understand😁.
@@VetteSource thank you!! 😁 I’ll try my best on it
Good deal, glad to hear. Let me know how it's going👍.
@@VetteSource I will 😁
Hi, I have a 1990 corvette. It runs great when driving but when I am a complete stop smoke starts coming from the right portion of the engine. I took it to a mechanic and he says the engine needs a total rebuild. Have you heard of the issue I’m experiencing?
Hey Scott, frankly it seems a bit premature for a mechanic to diagnose a smoking engine as needing a complete engine rebuild without a thorough inspection detailing the findings.
A leaking intake manifold, valve cover, or oil pan gasket can all cause the same symptoms you are describing.
My recommendation is to solicite opinions from multiple shops to get a sense of what might be going on. I like to look at Google reviews of places I am thinking of doing business with to get an idea of how they conduct themselves. Let me know how it turns out and if you need any further information.
My 93 keeps dying//stalling after 20 min. After it cools down it starts back up. Any idea???
Definitely could be an optispark issue, but I'm afraid you'll have to dig into it in real time to figure out what's going on. I would start with the coil mounted at the front of the passenger side head to check for bad/loose connection and proper operation once it has stopped running with a spark checker. If that checks out ok, I would start looking closer at the optispark itself.
Let me know how it's going👍.
My opti on my 95 trans am still works awesome zero issues with the distributer... 😂🎉
Yep, the later vented style optisparks seem to have less moisture intrusion issues.
Hello I'm new to corvette I own a 94 aqua blue 6spd what brand of optispark is a good quality? Thanks 👍
Generally speaking, I usually try and stick with OEM on the Corvette stuff. However, I'm not sure that GM is still offering an optispark replacement, so you're left to choose from the aftermarket suppliers.
I don't have a personal preference eight now, but looking at the catalog offerings there aren't many options available. I would say stay away from the cheaper units, and take a closer look at the Cardone piece and see what kins.of reviews it has. Let me know if you need any more recommendations.
Are their any seals that need to be replaced when doing this job ?
Hey Bill, other than water pump seals if you elect to replace the pump, everything on the optispark is pretty much self contained and sealed up like the older distributors so you shouldn't need to purchase anything extra.
My opti just failed today on my '96 LT4, what brands/models of replacement distributors do you recommend?
I would stick with the ACDelco remanufactured unit. The part # is 19383531 and is available on Amazon.
@@VetteSource Thanks for the help. Is that the later vented design?
Yes, all 94-96 units should have that as part of the design
Good video, a couple questions I want to throw out for anyone’s opinion. I have a 95, only 49,000 but expect some day I will have to deal with the dreaded optispark. When your opti dies, how many consider replacing with a superior system versus a “standard” optispark? Also, since the water pump comes out, Great idea to replace it, anyone consider replacing with an electric? Again, since the water system is drained, consider installing a dual-core radiator?
Thanks for the feedback, glad you enjoyed it. Personally I prefer stock installations on my replacement parts unless I am doing a hot rod build, plus the OEM usually is a better quality than most aftermarket pieces.
However, somebody that has gone that route may have more experience than me with those types of installs and can chime in.
Oem opti is the Best opti best optical sensor you can get, put a new cap and rotor on it when the time comes and keep it.
I need some help and advice.I fixed the ignition problem?.
Water pump and so on. The 94 runs great. Now when it comes up to temp the fans turn on then 5 seconds later it stalls. Crank no start.....again
Wow, that is an unusual problem. Under normal operation, the fan circuit doesn't have anything to do with the ignition system. I'm afraid this will require some electrical troubleshooting to figure out what is going on.
Does your engine harness look like it has any previous repairs or splices? After you get the no start condition, how long does it take before it wants to crank back up again?
Usually a couple hrs. Maybe overbite.
When I noticed what was happening I cranked it and let it run. At temp it cut off. I can't remember is the fans cut off too like a complete power failure I'll look next time. Harnesses are fine
Ok, it's possible you have a bad ground connection. I would check those first. If those check out, I would start looking at the ECM and harness connectors.
The only common connection location is the ECM. All roads lead to the company I researched that sells them preprogrammed You just provide your VIN.
Plug and play
Yep, not a bad option but not that cheap anymore. How much are they charging for a programmed unit?
Optispark sounds like something out of the transformers movie lol.
Good one, never thought about that👍.
Dump the optispark and go with Torqheads 24X system, as a bonus gain 25 to 50 hp and torque and a OB11 PCM.
Good info, thanks for sharing👍. Quite a few of the aftermarket suppliers have come up with optispark alternatives. I don't think I've heard of this system. I'll have to look into it further.
@@VetteSource I've had it in my 94 Z28 for 2 years now and it works great. It's just as easy to install as it is to replace the optispark. I got to know Paul the owner/designer very well and he's glad to answer any questions you may have. My optispark died on the road, my water pump was weeping slightly and it wipped out the bearing causing it to seize and the spline drive shaft broke off in the cam sprocket with 87,000 miles on the car.
The best thing about Torqhead is it's plug and play, no wire splicing. I even brought a spare PCM from him for only $350.00. All the other sensors and coils are AC Delco off the shelf parts. Now I have an OB11 computer and my scan tool gives me so much information.
Sounds like a pretty good system, I will be sure to check it out👍.
Good point for somebody looking into the conversion.
I have a 1993 LT-1, it also got and run's real rough. Have air dried everything, any Idea's
unfortunately the early units are prone to internal wear of the crank sensor and even with cleaning still don't want to function correctly. Might be easier to replace at this point rather than spend extra time on troubleshooting. Thanks for watching👍
Should that seal behind the opti spark be switched out? And the top n bottom also?
Hey Roberto, definitely want to change out for new seals as they tend to dry out and shrink with time. I believe the new units will come with replacement seals
I hear there's an ls pcm wire to replace the opti? Good or bad?
I've heard about it from a few different sources, but haven't ever been able to personally test it for durability and compatibility. Let me know if you have the information on it, and I will give it a closer look.
@@VetteSource looks like it's really iffy checking the vette forums, some opt to keep the opti attached but use the ls wires and have the voltage isolated to the black box controller which makes the system think the opti is good albeit its just not on, and some report the car is fine when you take it out and just use the black box, i think to stay safe i would do the first option albeit you still have to change the opti if it dies, you have a gained benefit of being able to control spark and the problem of the opti dying from water, i think the best more bulletproof option is the ventilated opti though which seemed to fix the problem and no ecu problems. 🤷♀️ it really astounds and amuses me the way people fix problems in the most ingenious ways with these cars 😂
Honestly it sounds kind of like a Rube Goldberg Machine. Not sure if you've heard of them, but it's essentially an overly complicated way to solve a minor problem. I've seen quite a few of these "workarounds" on newer cars when the electrical issues couldn't be figured out.
Optispark's are dead nuts reliable and typically last well over 200,000 miles without any issues. My last optispark was changed out at 300,000 miles. Everyone wrongly assumes that the optispark is the problem when it is typically the spark plug wires that need replacing. The ignorance and propaganda about these LT1 engines and the optispark allows me to pick them up used for song. I mean, come on, do you really think you'd get 2, 3 or 4 bad optispark's in a row? Lol.
I think you're right that under normal consistent usage these things will are pretty reliable. However, Corvettes are often bought as "toys" and don't see daily use. That's when most of the problems start to occur with water pump seals and gaskets drying out and moisture accumulation. Thanks for watching👍
wow,,i have 121k on my 92,,and it runs well,,,thks for talkin me into keeping it,,i love the car,,,bright red,,red int,,,,good car
drive them as much as u can,,,your saying????
Yep, C4's are meant for the open road. Like driving a high powered go kart around.
As much as you can make an excuse for, unless you need to take a bunch of people somewhere.
As I drive down the road my sys keeps coming on with different numbers but my car runs fine my OBD doesn’t have the sys codes
Have you tried putting the BCM in diagnostic mode using the DIC switch?
Thanks for sharing this video. I subscribed. I washed my engine bay on my 94 Z28 and it ran like crap. I let it dry after the engine was at operating temps for a few hours. Still miss fires. How long do you think it takes before all the moisture evaporates??? if it does??
No problem, thanks for the sub. The 94 should have the moisture vent built into it, but like you can see in the video sometimes that crusty material will collect inside the cap causing driveability problems.
I've seen people use heat guns and even park the car on a hot street surface during the summer in an effort to evaporate the residual moisture. At the worst it doesn't do anything, but at least you can give it a shot before having to take the water pump out to get at it.
@@VetteSource Thanks for your reply. I'm hoping the moisture will evaporate by morning. We will see. It ran perfectly before I pressure washed the engine. And I was aware of not spraying the water pump area.... opti spark. I thought the vent on the opti spark was on the 96-97 LT1??
It may have been 95 and later LT's, I may be misremembering. Also, I should have said hair dryer and not heat gun, that would result in a few melted pieces😁
@@camaro69green31 so what happened? I opened the coolant bypass hose and it spelled water on it 💩
Also check the ignition module
Yep, good point. Thanks for sharing👍.
My license is suspended for medical but I dream of getting my license back and getting a C4 Vette.
If I get to live my dream one day, do you recommend the L98 vettes or the LT1 vettes?
Is the Lt1 worth some of the headaches?
Both engines have their individual strengths and weaknesses, but for overall day to day enjoyment, I would look for a nicely kept 95-96 C4. They are well built, awesome road cars, and quite comfortable serving as a daily driver. The best part is that they are seriously undervalued right now, and can be had for a song compared to how expensive they were when new.
@@VetteSource thanks so much for replying.
I hear on reddit all the time that for the price of a well sorted lt1 6 speed C4 you may as well just pony for a C5. Any truth to that?
You seem to know your shit!
@@Jason-fp7vi those words are usually spoken by people who have never driven a C4😂. While C5's are great cars, I prefer the driving feedback you get from a C4 vs the C5. Plus the electronics are becoming problematic on the C5's. They have a high failure rate of things like the EBCM and other modules and wiring that can be costly and time consuming to repair.
My 89 Vette stalled while driving now cranks but won't start would you suggest me replacing the distributor cap first it's obviously getting no spark
Distributor cap probably isn't going to do it. I would start by checking for power to the distributor first, and if that checks out, I would take a look at the ignition module first. Oddly enough, a bad rotor can also cause a no start condition. Let me know how it turns out👍
Second time for me. I HHHAAATE this design. Compounded by the pre vented version.
Yea, the earlier units without the vent are easily damaged by moisture contamination. Thanks for the comments👍.
Hey man. I love your videos. I am on the lookout for a C4 LT4. Would you take a LT4 on long roadtrips where the car sits outside in the rain at night and drives in any sort of conditions in spring, summer and fall time? The optispark is good as long as you dont get it wet from underneath like a carwash or a flooded road for example? Are there parts available for the LT4?
Max, glad your enjoying the videos, appreciate the feedback👍. The later C4's are definitely very capable daily drivers in all types of weather and driving conditions. Like you said, avoid the carwashes and flooded roads and you should be fine. In fact the Aqua LT4 youve seen here in the channel gets parked in the driveway and driven as often as possible, regardless of the weather conditions.
Thanks for the reply. Cant wait to get my hands on a C4. Its the coolest car in the world
Yep, it will bring a smile.ro your face every time your behind the wheel.
Fuellechange
Channgefueppine
OMG!! I'll bet distributor parts are super expensive, just to add insult to injury. God bless the HEI in my '88.
They started out being rather expensive, and are still a bit more expensive than the HEI, but several aftermarket suppliers have stepped up to improve the design to ensure reliability. Thanks for the comment👍
$575 for the MSD and your troubles are over.
Yep, those are a good option. 👍
Please take a look at my video. 95 impala ss bad misfire only on pass side, driver side no problem. took pass head of to check for stuck valves no problem there. plugs on pass side swapped from drivers side didn't fix it. I'm lost on this one unless there is a bad injectors (all 8 have good 12 volts and good ground) any suggestions would be appreciated. and yes removed the Opti to look for problem under the, cap on the pass side clean.??
Dantae, looking at the video it looks like you are going to have to dig a little deeper into the fuel and ignition system to find your problem. I would start by disconnecting your fuel injectors and spark plugs wires one by one on the passenger side while its running to see if you get any change in the way it runs. That way you can isolate which cylinder is having the problem and go from there. Let me know how that goes.
After watching ur video I'm not going to send the ECU off to get checked, I also have a 1993 corvette and it's no start, no spark, everything else was checked and changed I really didn't want to go through all of this but nothing else I did or changed worked so I guess I'm doing the opti spark 😡😡😡😡
yea, that would be a good start
Yo cambié la whater pomp y después espeso a fallar tiembla un poco y no tiene la misma potencia, alguien me podría ayudar
Puso un distribuidor optispark cuando cambio la bomba del agua?
@@VetteSource No cambie el Optispark pero ya lo solucione el problema era un cable que estaba desconectado del distribuidor pero igual muchísimas Grasias seguiré mirando sus videos
Gracias a ti y avisame si necesitas algo mas.
@@VetteSource Disculpa por tanta pregunta amigo , pero me podrías decir cómo purgarlo . Ósea mi Corvette se le sube la temperatura hasta 235 y después prende el primer abanico , me dijeron que lo purgara para sacarle todo el aire al sistema pero no se como hacerlo ,si me pudieras dar algunos tips te lo agradecería muchísimo de antemano muchas Grasias .
How is it a problem takes a lot of miles to go bad it's not a flaw on a normal motor you would have put several caps wires and rotor button stuff last close to a 100 thousand miles pretty awesome set up
You're correct, it's not a bad setup
However, I think what I was referencing was the inherent difficulty in accessing and changing the unit out versus a good old fashioned cap and rotor. That along with the higher cost of the replacement parts has turned people off to the system.
If someone out of 150 comments hasn’t said it, my H/Balancer was a horses a…. to get off.
🤣 you are VERY correct. There isn't much room to work in there with the appropriate tools to get that thing off of the hub. However, did you notice the 3 bolts that separate the balancer from the hub shaft? They designed it with a built in hack so you could get the balancer off in stages rather than trying to get everything off at once.
Could really use your expertise my lt1 gets gas and spark but won’t start 🤔
Yep, that is frustrating when you have that happening. Have you verified if the injectors are pulsing during cranking?
@@VetteSource haven’t checked the back story I drove the car perfectly fine like 3 days before parking it. went back to drive it now it jus turns over
Gotcha, if you have confirmed proper fuel pressure at the rail of 42-46 PSI and spark at the cylinders I would guess your having a fuel injector pulse issue during cranking which may end up being a ECM issue.
@@VetteSource so update I found out it was indeed the opti spark even tho the car still was getting spark but the problem is solved 😁💪🏾
Great, that's good news. Glad to hear you got it back on the road. I'll be tearing into the 97 Aqua LT4 soon. The water pump just started leaking the other day so I'll be tearing it down to replace everything.
LT1 reminds me or N* a PITA to work on
It's not the easiest but definitely not the worst.
Man you really have an engine oil leak bad you know thats bad right very bad for the all WIRING on the car or truck and a fire hazard to
Hey Javier, funny thing is that most of the car this engine was pulled from burned to the ground due to a battery charger left on it for too long. The leaking oil was the least of its problems😁. Thanks for the comments.
would rather have a distributer way easier to work on . another nightmare designed by engineers that don't pay to fix it
I think quite a few of the old school mechanics feel the same. Thanks for the comments👍.
@@VetteSource I could see these cars being LS swapped. I drove my stock GMC pick up through a river and it ran fine.ls has way better ignition system
Yea, definitely a potential failure point, but if kept up with maintenance wise the later C4 optisparks last for many years. My 2 96 LT4 Corvettes, one with 23K miles and the other with 135K are both running their original systems.
Extremely stupid setup.
Definitely was a puzzling decision to put it there. Thanks for watching👍
Eliminate Optispark. Delteq makes an excellent replacement.
Thanks for sharing the info👍
This is weird watching, u have an almost identical voice to mine.
😁, now that's funny. Do yiu have any videos on YT? I'll have to check them out to compare👍.
@@VetteSource no not any that im vocal on. Just found it funny we sound so similar n i have n lt1 im working on so it felt like i had blacked out n worked on my car n someone else taped it haha
That is funny😁. Small world isn't it. Have a great weekend👍
@@VetteSource you do the same
👍👋
👍
H16 code for the bad opti.
Cool, thanks for sharing the info👍
Wath does SYS mind
SYS is a message generated by the BCM alerting you to a trouble code stored or something else wrong within the data line circuit. It will even flash "SYS" if you have a low battery voltage condition.
It's almost an engine out service.
For this one at least, but at least you have more room to work on the front of the engine with the hood up and out of the way. Thanks for watching👍
👉👍👍👍👍👍🙏
Thanks for watching👍
👉Nobody thought to put a bag or a rubber boot over this thing to keep moisture out? I had a brand new 96 back then, and if I left it outside, which I did, and if it rained that week, it didn't want to start by the weekend.. 😭
Amazingly, this car ran strong for well over 100,000 miles before the previous owner burned it to the ground in his driveway after leaving a battery charger hooked up to it for too long. Of course, maybe the oil leaks all over the front of the distributor helped keep some of the moisture out😁.
Wasn't those weak
Why dont you try cleaning it once...
This was a motor from a burned salvage car that I dismantled for parts. Not much reason to clean it up until it gets freshened up to install in another car. Thanks for the feedback👍.
I will NEVER buy another Vette with that STUPID OPTISPARK!!!!!
My 94 is awesome.....when it runs.
I've thrown enough money at it to buy another one.
From dream car to nightmare.
They say the LT1 is dependable.
NOT
Hey Paul, I understand your frustration. Sometimes when you have an optispark failure, it can be a challenge to find quality components or qualified technicians to make it work correctly again. Hope it works out for you. The 94's are great cars.
I made it to the store 2 miles down the road and back. Things are looking up
There ya go. Keep starting up and driving that old guy around. It's good for it.
By the way... It's not a motor, it's an engine.
Yea, six of one half a dozen of another😂. Thanks for watching👍
Motor is acceptable also.......just think...it's Ford MOTORsport not Ford Enginesport. :)
Good example, thanks for sharing👍