Fantastic process, thanks for sharing it with us. Don't worry about editing fancy videos, that's not what we're here to see. Your format is good enough!
"you're not always going to find it with smoke ' TRUTH !! had a 08 impala here with high fuel trims that dropped as rpm went up. vacuum leak for sure. did a smoke test... no leaks. started pinching hoses. pinched the brake booster hose and engine started to stumble. spraying where the master bolts to the booster... boom !! thats when i had the awakening that youre not always going to find it with smoke. btw its super easy to follow along with your stories . great work as always
Good morning joe , you had to bring the car back to stock condition, before you could diagnose the problem.. my old boss use to explain to the customers that man made problems are the hardest and most expensive to fix .. your diagnostic skills and your methodical approach and lazer focus, is outstanding,
Joe, I really loved this video, because it highlights something that few people seem to talk about. Which is a leaking brake booster. I bet a lot of techs have been stumped by this type of problem. My first encounter/learning experience with this was very memorable. It was approximately 10 years ago, back when I knew FAR less than I know today. Of course that’s not implying that I’m any genius now though, lol. It was an early 2000s Geo Prizm, basically a Toyota Corolla. It is a mass air EFI system. A persistent P0171 was the only code. The freeze frame data indicated that it was happening only at idle, in Drive, 0 MPH. The first thing I did was check for any vacuum leaks or air bypassing the MAF, but despite very thorough checking, I could find no leaks of any kind. I cleaned the MAF, no difference. Put in a new Denso MAF, still no difference. It was killing me, I checked all the basics, and couldn’t figure it out. I was about to give up and give the car back to the lady, who was a family friend luckily, so she could take it to the dealer like she wanted to. But I wanted to go over everything again, one last time, to make sure I didn’t miss something somehow. So I sat in the car with my scan tool, idling, in Drive, vehicle stopped, all the windows up. And I was kind of getting into a zen like state where I was trying to make the most of my senses, sight and sound particularly. And as I was sitting there for a few minutes, I thought I heard a faint hissing sound. I thought hmm, where could that be coming from, all the windows are up, no accessories are on. I quickly realized that the only possibility could be the brake booster. So I put the parking brake on, took my foot off the brake pedal, and it seemed like the hissing went away. Stepped on the pedal again, hissing seemed to return. Then I did the same pedal apply and release test, but this time watching the O2 sensor waveform. When I stepped on the pedal, I saw a sudden and prolonged drop to 0 mV. I now had confirmation that my suspicion was correct, it was a leaking booster that was causing all this trouble. But what’s so tricky about it, is that it is a vacuum leak that exists ONLY when the brake pedal is depressed. The commonly used methods of finding a vacuum leak would never find it. Ever since then, whenever I’m checking for vacuum leaks, I always pay attention to the booster as well. Oh and btw, I couldn’t help but notice what almost certainly appears to be a SB Chrysler header gasket hanging on the wall. Mopar guy here 😁
Awesome brother. I actually have a video on an Explorer that my buddy owns that did the same thing, but the truck wanted to stall from the sudden lean condition. It made for a good video and was cool to see caught on camera.
Oh I forgot to mention Joe, that car would actually stall sometimes from the condition as well. I think she told me one time that it actually died in the middle of an intersection, trying to make a turn. Obviously that freaked her out, and she was scared to drive the car.
Some seriously good troubleshooting skills on display, nice work. Crap parts will be an issue going forward as older cars go into classic mode and parts are NLA. I am having the issue right now with a 97 BMW 540.
Same here on my 92 BMW 735iL. Good luck trying to find an OE Bosch idle air control valve, air flow meter or throttle body! I found that the best recourse is to use known-good used parts. I'm dealing with a shaking engine with a minor hunting at low RPM's (idle and reverse/drive off-throttle). Very difficult to find a source for the issue, and the mechanics that looked at it weren't exactly excited. I wish I had someone like Joe or Eric O in my area.
Iǘe watched a lot of car repair videos but this is the first one that explained fuel trims in a way that was easy to understand. Really enjoyed watching.
Nice to see there’s still some guys out there that actually use their head to troubleshoot problems. Most rely on a computer to spit out a code with step by step instructions and the up to date labor rates to charge! I have a 86 C4 as well as a 70 Impala. Not much help out there that knows what’s front and what’s back... Good work and thanks for sharing!
This video actually helped alot, I am dealing with alot of the same issues you mentioned and have read alot of forums with no resolution. But at least with your help I know which direction to start looking. Thank you...
Great video and diagnosis on a OBD1 vehicle. That old SnapOn brick is still a very useful tool, I still have mine that I bought brand new back when they first came out. Just a heads up on smoke testing. A lot of the brake boosters out there have a one way check valve on them. They open up when there is a vacuum source (engine running) to allow the booster to work but they close as soon as the vacuum source is turned off. If the valve is closed, it will not allow the smoke to enter the booster chamber. I remove the vacuum hose and check valve and stick the hose in the rubber grommet to check for booster leaks. Good job, keep the videos coming.
Yes sir. I should have mentioned that. I actually removed the valve also, and smoked it out of the vehicle. No smoke...But it is quite obviously broken. maybe something to do with the diaphram? I am honestly not sure...
An MT2500 nearly new?!! I bought one of these when they first came out and I still have it plus ALL the cartridges AND chip upgrades that were available right up to the end of availability. Personally, I found the "brick" to be one of the best tools I ever purchased for OBD-1 diagnostics! Nice bit of diag work, Joe...congrats on solving it.
Great video Joe! Anyone that doesn't realize how important fuel trims are to diagnosing drivability concerns really need to get educated on the topic. Understanding fuel trims is a basic foundation of fuel injection diagnosis.
Always informative. Dam good diagnosis. I remember years ago was at training and the instructor said eventually we will just a crankshaft, piston going up and down don't be intimidated, it's still just an engine. He said all the valves would be electronic. Just a side not, boy did I hate doing heater cores.
Joe I was just thinking after the fact, if you smoke the intake isn't there a one way check valve on brake booster. The check valve would only allow vacuum into the booster but wouldn't allow pressure like smoke vapour into the booster. Just a thought. Have a good day.
Joe's Auto Electric that's what makes us techs never get beat attitude. Maybe it was cracked in such away that when pressure applied it actually sealed it. I know have strange shit happen to me also. I remember when I used work on school buses. We were getting government inspections and they would fail use because the brake jounce had a bulge in it. We were quite upset they were finding this defects because it was the brake
Dam big fingers. Anyway they pumped the brake pedal with electric over hydyolic as hard as could and that's when they bulged!!!!! Normally you slam the brakes on a panic stop. There test was not realistic but they would not admit they were wrong but you know how government inspectors are like. Catch on the flip side.
The old down the rabbit hole parts cannon, only they replace good parts with junk and broke what was not broke. Good save. Always like the tuned port motors. Similar to the one in my old 88 IROC.
@@JoesAutoElectric they're still respectable in today's world. 350 ft-lb torque is no joke, even if the hp rating seems like it. I really like TPI systems, they look cool and produce awesome torque. They don't breathe all that well, but there are fixes for that too. Mine is bone stock, don't even have an upgrade PROM in it. It's been fairly reliable, outside of the fuel injectors. Had to replace a temp sensor that was telling the computer it was -40 outside. That's adding a little bit too much fuel houston temperatures in open loop mode. Tuner pro clued me in on the part. When I did the injectors, I replaced the thermostat with a 180 and bypassed the throttle body water passage. I'm not too worried about icing here. These engines love low coolant temps and cold air, the factory wanted them to roast all the time. Oh yeah, I've been through a couple of fuel pumps over the years. That's not a lot of fun to do, but I refuse to cut a trap door through the floor pan. These cars are finally becoming worth something. The irony is that they're getting to be worth more than the corvettes from those days. The L98 was an awesome motor for its time.
Did you have an L98 350, or the 305? My 66 GMC has a rebuilt 305 HO motor from a 91 fbody. I only bought a short block, do it's missing the induction and roller cam. I put a summit 1102 cam in it and a two barrel Rochester, long tube headers and glass packs. I've got an edelbrock performer intake and an almost new holley 4 barrel, I just need to install it. I might change up the cam and go full roller when I do it. It's tied to a power glide, so it needs all the torque it can muster. With a four speed automatic, my truck would lead a different life than it does now. You can see it at www.jvdrivers.net
Often you wont get smoke through the brake booster because they have a one way valve in the line somewhere so they hold vacuum when you turn the engine off.. The smoke wont get through that valve.
Sounds to me like the last thing a customer should work on is his own Corvette. And certainly not his friends Vette without proper equipment. I just broke the holdown connecter on my Dodge Journey's computer. I have been disconnecting and plugging back in these two connectors to reset the computer so the cruise control works. After unplugging it works right for about a week each time. Last time I sprayed wd40 in the connectors but it still ran cruise control for a week before the little computer on the console would not turn on. I don't have enough money for a new computer as I am old. Looks like I will have to find the back connector cover. Thanks for the good videos.
i'll admit i got bit by a booster in my younger years. truck had other problems too which helped mask the problem. carbureted 6 cylinder. learned my lesson though.
Good find, ive ran into that as well the reason you couldn't see the smoke is due to the check valve in the booster stoping the pressure from the smoke machine. If you think its a booster check it with the check valve removed or just do what you did block the hose .
When I got my Trans Am I snapped the bolts for that shield over the distributor. If people tighten them too much, or don't use anti-seize on them... I never put it back on.
Hey Brother I started obd1 in Indiana when the clean air car check tested on a Dyno with a 5 gas analyzer. I M 93 test. Air pump diverter valves were a big issue. But your 100 % dead on balls the 1 wire o2 had to be grounded. Great explanation on block learn and integrator 0 to 255. 👍👍 128 14 : 1 ratio.
@@chrislore2681 those Dyno systems were designed for 50% load at 15mph if memory serves. However I know if a story from years back about a brand new corvette at a shop for an oil change. One if the knuckle heads decided it'd be a good idea to throw it in the Dyno and see how it did at high speed. Needless to say, the car, along with the shop owner's snap on box, and the Dyno were destroyed.
@@JoesAutoElectric .......... Yeah for some reason the knucklehead thought he had the floor it...... Probably because it was a 1990 LX notchback mustang..........
Damn Joe, they really screwed the pooch on the timing. Base timing disconnect still taped...wow..smh. Great call on the booster and trashing the aftermarket junk. You are kicking the problem child`s ass when others threw in the towel. Outstanding workmanship! I wish I lived closer so you could fix my gauge cluster in a `91 C1500 Silverado with moonie gauges.(hate em)..temp and oil gave up the ghost, senders are good, connections to them are solid. Needless to say, I don`t like moonie, but love the truck. Over 300k on the clock and finally had to replace the original distributor when the pickup coil`s plastic cover disintegrated. It fired right up with new distributor with timing connector disconnected. Set base timing, shut off and connected timing plug...runs like a champ. Thanks for sharing your diagnostic skills and train of thought. I appreciate it along with many others. Stay safe, God Bless.
As you know Glen (Ozzstar) and I have owned several Corvettes. I have had great luck with near zero issues on any of them but yes, you got a real zinger there. I enjoyed the story behind the ultimate fix because like you said, drive-ability troubleshooting can be related to any car.
Mario posted a video about not being able to find the smoke and he said use a laser point because the flash light will drown out the small amount of smoke but a laser won't. Might have helped? FYI. Tha ks for the content
Good find on the booster crack. I happen to have the exact same car ('88 C4 automatic). I bought it in 1989. It now has 216,000 miles. It's rotting away in my garage because it won't pass California smog tests. I threw EGR parts at it but no improvement. The car runs strong and idles well. But the California smog sniffer says NOX is off the charts (1595 PPM measured, max allowed is 545 PPM). These numbers are repeatable. I'm stuck - can't sell it, can't drive it.
@@JoesAutoElectric Fair question. My wife and I are in our mid-sixties now. Somehow, we ended up owning four cars. I'm assuming at 216,000 miles the mechanic will simply say, you need another engine or some major repairs. Being semi-retired and my wife being fully retired, we don't feel like dumping 5k into that car. That's probably more than it's worth. We'd rather use that money to go on another cruise - if the cruise lines ever start back up.
I generally check boosters with a vacum pump if i suspect a leak. You may want to try that for shits n giggles and see what results you get with that. Good video on working on older cars and trying to diagnose the real problems. To many hands and to many bad parts. Congrats on getting that brick, been looking at them to work on my older truck, still pretty spendy.
Hvac systems that have a vacuum reservoir will also have check valves. You can still use a smoke machine, but need to either bypass the valve, or simply change where you inject the smoke. Surprised this car didn't have a high brake effort complaint.
The heater core on this year Corvette is a pain to replace. If you take out the passenger seat put a board down and then work on your back below the dash you can change it without pulling the whole dash. The ignition distributor manifold cover plate is held in place by three small Torx head machine screws. They are usually very easy to remove but not always, and you will shear them off if you are not careful, like the screw missing in the video, which is probably sheared off. Often you have to add a little heat and get the screw to back off a turn or two, then add penetrating oil, let soak in and work the screw in and out while adding heat and more penetrating oil to free it up. The steel machine screw is mounted using machine threads directly in the aluminum manifold body without an insert or Heli-Coil, and as a result will be an excellent heat sink so adding heat you have to be careful to not add too much but also not to add too little. Once you free up the screw, and add WD40 it is easy to install. With the cover off, add WD40 to the threads and run the screws in and out a few times and the threads will lube up and the screw will not seize again. The MAF should be a Bosch OEM replacement. The fuel injectors do not look like OEM replacements. The original injectors on this year Corvette will tend to fail when hot. So, if one fails, it is best to replace all the injectors with a matched flow set. All of the rebuilt or new sets that I have installed on C4s 85 to 89 Corvettes have a dark body like matt black, maybe a very dark blue. As stated in the video it is relatively easy to spot the bad injector using the current clamp because it will look purely resistive and different from the other injectors. But, you have make sure you let them get very hot. So, before doing this test close the hood and let the idle until the cooling fan cycles a few times, then open the hood and do the test. You will hear the misfire most of the time as the car warms up. However, in the end you don't really narrow it down to which injector you just replace the whole set.
@@JoesAutoElectric Yes, I watched the complete video, and yes I assume that you know how to do the repairs. However, there are a lot of details not covered, which is okay based on the keeping the video concise. My comment was meant to give a little more detail on what I have experienced with the repairs. This is after all a very old car. Do you see any issues with my suggestions?
You know what...even though I've got a new Snap-On Solus Legend scanner I still have my OG MTG-2500, the graphing brick and all the adapters n stuff for old OBD1 stuff. Works wonders sometimes even though I have the adapter to use all those old adapters on the Solus Legend, the old Brick can still talk to some older stuff the Legend can't. Still something useful to have the diagnostic arsenal.
Great vid Joe. Pinching off that booster line was key. No. Knowing the fuel trim of that polder system. Did u get to use the MT 2500? Thanx for sharing your experience with us!!
Just went over all this with my cousin a couple of days ago. He changed the cat's and o2's and MAF and I was telling him about o2's and fuel trims and what not, I think he's been wasting money and possibly adding more problems unfortunately.
I'm so glad my 90 TPI car is a speed density system, no MAF for me. These are such simple systems, but can be really frustrating if you can't see all the ECM data because they are only OBD1. Moates makes the cable you need, if you have one of these. Tuner Pro is the software you want. These engines have junk fuel injectors that gradually short out and cause the engine to shutdown suddenly with no diagnostic code. Bosch makes some that will fit the rails and connectors.
The check valve at the booster will not allow pressure through, its one way,, so no surprise you didn't see smoke there. If you had you'd have a bad booster and check valve.....
That blue oval on your shirt means you've seen some bizarre mixtures of American, Asian, and European automotive technology. That spells _experience,_ and _ability_ to diagnose. That means you are the proper technician to addresss issues on any bizarre combination of all of the above, be it GM, Ford, Dodge, Mazda, Honda, Toyota, MCB, or Bimmer. That is why I like you. Masters that can stand back and decipher (seriously) stupid shit like this deserve the salutes you unfortunately never receive. You are the kind of guy I wish I could send my (parts store) customers to.
Dang Joe!! I wish you were in the SF Bay. I would try and become a customer of yours!! In my business, I send 2-3 cars per week to the shop and most of these guys only want to do brakes. They really do not want to troubleshoot problems. Talent & skill like yours is a lost art. You gained a sub!
Great job on this one..... Always tough to start over after 3 people have looked at it.... Ugh. I'm in a different industry, but we get that too... then you spend all day wondering, was it like that?? Or did somebody do this, thinking it would help? What is going on here?? This can't be the way it was originally, right???? Gives me a headache just thinking about it.... You remind me a lot of one of my friends... He can fix anything, as long as he doesn't run out of smokes... Heh heh! Just kidding Sir. No, how he reminds me of you is, he might look a little rough around the edges, but he is a genius on cars, especially Japanese stuff... Toyota & Nissan, he's a walking encyclopedia.... An Encyclopedia that needs a steady diet of coffee and Marlboro Lights to keep functioning at a high level....
Nice OBD1 scanner, I wish I had friends like you. Question..is there a way to use a laptop to read OBD1? Right now if the money lights up, I`m jumping the port to read flashes caveman style...lol
you would think smoke would have been pouring out that plastic booster! spectra mass air ?? what? well theres a seat for every ass! next job.... an opti i think in 87 they went multiport what a big improvement
Cost less to have someone who knows what they’re doing in the first place. Good Job Joe!
Ya that's always the case
I bet you felt so good when you found that crack you could have tap danced!! Really enjoyed this one Joe, you are my inspiration. Matt from Florida
Fantastic process, thanks for sharing it with us. Don't worry about editing fancy videos, that's not what we're here to see. Your format is good enough!
I appreciate that!
Great job brother most vette are a pain in the ass to work on we need more techs like you in this trade
Cheers
Great diagnosis, and the way you tell the story awesome, I could visualize while you were talking!!!
"you're not always going to find it with smoke ' TRUTH !! had a 08 impala here with high fuel trims that dropped as rpm went up. vacuum leak for sure. did a smoke test... no leaks. started pinching hoses. pinched the brake booster hose and engine started to stumble. spraying where the master bolts to the booster... boom !! thats when i had the awakening that youre not always going to find it with smoke. btw its super easy to follow along with your stories . great work as always
Smoke wont flow into the booster due to the vacuum check valve. I pull check valve and smoke the booster directly.
This was with the check valve disconnected.
Good morning joe , you had to bring the car back to stock condition, before you could diagnose the problem.. my old boss use to explain to the customers that man made problems are the hardest and most expensive to fix .. your diagnostic skills and your methodical approach and lazer focus, is outstanding,
Those old snap on Bricks are awesome. I have a friend that still has one from back in the day. I borrow it once in a while for old stuff!
Joe, I really loved this video, because it highlights something that few people seem to talk about. Which is a leaking brake booster. I bet a lot of techs have been stumped by this type of problem.
My first encounter/learning experience with this was very memorable. It was approximately 10 years ago, back when I knew FAR less than I know today. Of course that’s not implying that I’m any genius now though, lol. It was an early 2000s Geo Prizm, basically a Toyota Corolla. It is a mass air EFI system. A persistent P0171 was the only code. The freeze frame data indicated that it was happening only at idle, in Drive, 0 MPH.
The first thing I did was check for any vacuum leaks or air bypassing the MAF, but despite very thorough checking, I could find no leaks of any kind. I cleaned the MAF, no difference. Put in a new Denso MAF, still no difference. It was killing me, I checked all the basics, and couldn’t figure it out. I was about to give up and give the car back to the lady, who was a family friend luckily, so she could take it to the dealer like she wanted to. But I wanted to go over everything again, one last time, to make sure I didn’t miss something somehow.
So I sat in the car with my scan tool, idling, in Drive, vehicle stopped, all the windows up. And I was kind of getting into a zen like state where I was trying to make the most of my senses, sight and sound particularly. And as I was sitting there for a few minutes, I thought I heard a faint hissing sound. I thought hmm, where could that be coming from, all the windows are up, no accessories are on. I quickly realized that the only possibility could be the brake booster. So I put the parking brake on, took my foot off the brake pedal, and it seemed like the hissing went away. Stepped on the pedal again, hissing seemed to return.
Then I did the same pedal apply and release test, but this time watching the O2 sensor waveform. When I stepped on the pedal, I saw a sudden and prolonged drop to 0 mV. I now had confirmation that my suspicion was correct, it was a leaking booster that was causing all this trouble. But what’s so tricky about it, is that it is a vacuum leak that exists ONLY when the brake pedal is depressed. The commonly used methods of finding a vacuum leak would never find it.
Ever since then, whenever I’m checking for vacuum leaks, I always pay attention to the booster as well.
Oh and btw, I couldn’t help but notice what almost certainly appears to be a SB Chrysler header gasket hanging on the wall. Mopar guy here 😁
Awesome brother. I actually have a video on an Explorer that my buddy owns that did the same thing, but the truck wanted to stall from the sudden lean condition. It made for a good video and was cool to see caught on camera.
Oh I forgot to mention Joe, that car would actually stall sometimes from the condition as well. I think she told me one time that it actually died in the middle of an intersection, trying to make a turn. Obviously that freaked her out, and she was scared to drive the car.
Good to know . That could keep your head in a knot .
If the booster wasn't plastic it would still be working like mine on a 62 Impala.
Some seriously good troubleshooting skills on display, nice work. Crap parts will be an issue going forward as older cars go into classic mode and parts are NLA. I am having the issue right now with a 97 BMW 540.
Same here on my 92 BMW 735iL. Good luck trying to find an OE Bosch idle air control valve, air flow meter or throttle body!
I found that the best recourse is to use known-good used parts.
I'm dealing with a shaking engine with a minor hunting at low RPM's (idle and reverse/drive off-throttle). Very difficult to find a source for the issue, and the mechanics that looked at it weren't exactly excited. I wish I had someone like Joe or Eric O in my area.
Iǘe watched a lot of car repair videos but this is the first one that explained fuel trims in a way that was easy to understand. Really enjoyed watching.
Glad you liked it!
Nice to see there’s still some guys out there that actually use their head to troubleshoot problems. Most rely on a computer to spit out a code with step by step instructions and the up to date labor rates to charge! I have a 86 C4 as well as a 70 Impala. Not much help out there that knows what’s front and what’s back... Good work and thanks for sharing!
Glad to help
Great job on figuring it out. There should be more people with your passion in the automotive world? 👍👍
For sure you made this customer happy. Professional job
This video actually helped alot, I am dealing with alot of the same issues you mentioned and have read alot of forums with no resolution. But at least with your help I know which direction to start looking. Thank you...
Keep us posted on the progress. Glad to help out.
Joe, great job as always. Keep the videos coming. Thanks!
Thanks, will do!
Wow, great find. I would never even think to look at the booster. Love your videos.
Thanks for watching!
Joe with that pack of Marlboros in his pocket..........that can be a most important tool sometimes........ Awesome work is always
You can't trust a mechanic that doesn't smoke. ;)
@@tonyfremont ..... That is very true
@@tonyfremont Hahahahaha! That's right!
Robert Burley that’s smart
Another well done, backing up a few steps and looking at the bigger picture.
Thanks 👍
Great video and diagnosis on a OBD1 vehicle. That old SnapOn brick is still a very useful tool, I still have mine that I bought brand new back when they first came out. Just a heads up on smoke testing. A lot of the brake boosters out there have a one way check valve on them. They open up when there is a vacuum source (engine running) to allow the booster to work but they close as soon as the vacuum source is turned off. If the valve is closed, it will not allow the smoke to enter the booster chamber. I remove the vacuum hose and check valve and stick the hose in the rubber grommet to check for booster leaks. Good job, keep the videos coming.
Yes sir. I should have mentioned that. I actually removed the valve also, and smoked it out of the vehicle. No smoke...But it is quite obviously broken. maybe something to do with the diaphram? I am honestly not sure...
Excellent video! Funny how people try to fix things when they don’t know how they work and that’s pretty fundamental to repairing anything.
Exactly!
Excellent job fixing the car Joe!
Thanks 👍
An MT2500 nearly new?!! I bought one of these when they first came out and I still have it plus ALL the cartridges AND chip upgrades that were available right up to the end of availability. Personally, I found the "brick" to be one of the best tools I ever purchased for OBD-1 diagnostics! Nice bit of diag work, Joe...congrats on solving it.
Take a bow joe..good diagnosis
Awesome video Joe, thanks
From another Joe
Great video Joe! Anyone that doesn't realize how important fuel trims are to diagnosing drivability concerns really need to get educated on the topic. Understanding fuel trims is a basic foundation of fuel injection diagnosis.
Always informative. Dam good diagnosis. I remember years ago was at training and the instructor said eventually we will just a crankshaft, piston going up and down don't be intimidated, it's still just an engine. He said all the valves would be electronic. Just a side not, boy did I hate doing heater cores.
Joe I was just thinking after the fact, if you smoke the intake isn't there a one way check valve on brake booster. The check valve would only allow vacuum into the booster but wouldn't allow pressure like smoke vapour into the booster. Just a thought. Have a good day.
100% true. I removed the check valve though...even did this off the car. Crazy, no?
Joe's Auto Electric that's what makes us techs never get beat attitude. Maybe it was cracked in such away that when pressure applied it actually sealed it. I know have strange shit happen to me also. I remember when I used work on school buses. We were getting government inspections and they would fail use because the brake jounce had a bulge in it. We were quite upset they were finding this defects because it was the brake
Dam big fingers. Anyway they pumped the brake pedal with electric over hydyolic as hard as could and that's when they bulged!!!!! Normally you slam the brakes on a panic stop. There test was not realistic but they would not admit they were wrong but you know how government inspectors are like. Catch on the flip side.
Great tutorial.
Thank you! Cheers!
It takes some big cojones to take on a mess like this. Once again Joe ain’t scarred!
Interesting. Never seen that before. Thanks Joe.
Thanks for watching!
The old down the rabbit hole parts cannon, only they replace good parts with junk and broke what was not broke. Good save. Always like the tuned port motors. Similar to the one in my old 88 IROC.
Yes sir. My old GTA (1989) had the L98 engine with some work done to it. For it's time, it ran pretty good.
@@JoesAutoElectric they're still respectable in today's world. 350 ft-lb torque is no joke, even if the hp rating seems like it. I really like TPI systems, they look cool and produce awesome torque. They don't breathe all that well, but there are fixes for that too. Mine is bone stock, don't even have an upgrade PROM in it. It's been fairly reliable, outside of the fuel injectors. Had to replace a temp sensor that was telling the computer it was -40 outside. That's adding a little bit too much fuel houston temperatures in open loop mode. Tuner pro clued me in on the part. When I did the injectors, I replaced the thermostat with a 180 and bypassed the throttle body water passage. I'm not too worried about icing here. These engines love low coolant temps and cold air, the factory wanted them to roast all the time. Oh yeah, I've been through a couple of fuel pumps over the years. That's not a lot of fun to do, but I refuse to cut a trap door through the floor pan. These cars are finally becoming worth something. The irony is that they're getting to be worth more than the corvettes from those days. The L98 was an awesome motor for its time.
Did you have an L98 350, or the 305? My 66 GMC has a rebuilt 305 HO motor from a 91 fbody. I only bought a short block, do it's missing the induction and roller cam. I put a summit 1102 cam in it and a two barrel Rochester, long tube headers and glass packs. I've got an edelbrock performer intake and an almost new holley 4 barrel, I just need to install it. I might change up the cam and go full roller when I do it. It's tied to a power glide, so it needs all the torque it can muster. With a four speed automatic, my truck would lead a different life than it does now. You can see it at www.jvdrivers.net
Hopefully you get some nice weather for the test ride
Fantastic video
A wedge with some tires on it. LOL
@5150 OU812, lolol
A jet with tires! My C4 has 18K miles on it 😁 Wepaa!
that needs a block of C4 detonated inside it :))
I can see how a car like that would try your patience, but you stuck with it and won---great job
Thank you
Often you wont get smoke through the brake booster because they have a one way valve in the line somewhere so they hold vacuum when you turn the engine off.. The smoke wont get through that valve.
Indeed...but the valve was removed.
Sounds to me like the last thing a customer should work on is his own Corvette. And certainly not his friends Vette without proper equipment. I just broke the holdown connecter on my Dodge Journey's computer. I have been disconnecting and plugging back in these two connectors to reset the computer so the cruise control works. After unplugging it works right for about a week each time. Last time I sprayed wd40 in the connectors but it still ran cruise control for a week before the little computer on the console would not turn on. I don't have enough money for a new computer as I am old. Looks like I will have to find the back connector cover. Thanks for the good videos.
i'll admit i got bit by a booster in my younger years. truck had other problems too which helped mask the problem. carbureted 6 cylinder. learned my lesson though.
Great job in diagnostics.
Thank you!
Just take it to someone good the first time, awesome video .
Love the videos your down to earth also you keep it real call it as you see it keep them coming
I appreciate that
i have a 95 riviera thats only scanner that will read the car, love your videos
Thank you.
Good find, ive ran into that as well the reason you couldn't see the smoke is due to the check valve in the booster stoping the pressure from the smoke machine. If you think its a booster check it with the check valve removed or just do what you did block the hose .
I should have mentioned int he video, the check valve was removed
Sick underrated channel bro !
When I got my Trans Am I snapped the bolts for that shield over the distributor. If people tighten them too much, or don't use anti-seize on them... I never put it back on.
Hey Brother
I started obd1 in Indiana when the clean air car check tested on a Dyno with a 5 gas analyzer. I M 93 test. Air pump diverter valves were a big issue. But your 100 % dead on balls the 1 wire o2 had to be grounded. Great explanation on block learn and integrator 0 to 255. 👍👍
128 14 : 1 ratio.
Oh yes I remeber that test. Remember in Jersey we had the same dyno testing with 5 gas. And I hate those damned diverter valve tubes on these engines.
....,.. I remember the dinos they put my 90 notchback on it...... thought that thing was going to come right off.....lol
@@chrislore2681 those Dyno systems were designed for 50% load at 15mph if memory serves. However I know if a story from years back about a brand new corvette at a shop for an oil change. One if the knuckle heads decided it'd be a good idea to throw it in the Dyno and see how it did at high speed. Needless to say, the car, along with the shop owner's snap on box, and the Dyno were destroyed.
@@JoesAutoElectric .......... Yeah for some reason the knucklehead thought he had the floor it...... Probably because it was a 1990 LX notchback mustang..........
Nice save joe
Damn Joe, they really screwed the pooch on the timing. Base timing disconnect still taped...wow..smh. Great call on the booster and trashing the aftermarket junk. You are kicking the problem child`s ass when others threw in the towel. Outstanding workmanship! I wish I lived closer so you could fix my gauge cluster in a `91 C1500 Silverado with moonie gauges.(hate em)..temp and oil gave up the ghost, senders are good, connections to them are solid. Needless to say, I don`t like moonie, but love the truck. Over 300k on the clock and finally had to replace the original distributor when the pickup coil`s plastic cover disintegrated. It fired right up with new distributor with timing connector disconnected. Set base timing, shut off and connected timing plug...runs like a champ. Thanks for sharing your diagnostic skills and train of thought. I appreciate it along with many others. Stay safe, God Bless.
As you know Glen (Ozzstar) and I have owned several Corvettes. I have had great luck with near zero issues on any of them but yes, you got a real zinger there. I enjoyed the story behind the ultimate fix because like you said, drive-ability troubleshooting can be related to any car.
Right on Wyatt!!
Great job as usual 😃
Thank you! Cheers!
Freaking awesome work.
Mario posted a video about not being able to find the smoke and he said use a laser point because the flash light will drown out the small amount of smoke but a laser won't. Might have helped? FYI. Tha ks for the content
Indeed a laser can be helpful, but this was even smoked off the car with the crack in plain view. Saw nothing.
that year the 350 in pick up trucks needed a brace to prevent the break booster from cracking could add a brace for the vett .
Good find on the booster crack. I happen to have the exact same car ('88 C4 automatic). I bought it in 1989. It now has 216,000 miles. It's rotting away in my garage because it won't pass California smog tests. I threw EGR parts at it but no improvement. The car runs strong and idles well. But the California smog sniffer says NOX is off the charts (1595 PPM measured, max allowed is 545 PPM). These numbers are repeatable. I'm stuck - can't sell it, can't drive it.
Why not bring it to a shop who is capable of diagnosing it properly?
@@JoesAutoElectric Fair question. My wife and I are in our mid-sixties now. Somehow, we ended up owning four cars. I'm assuming at 216,000 miles the mechanic will simply say, you need another engine or some major repairs. Being semi-retired and my wife being fully retired, we don't feel like dumping 5k into that car. That's probably more than it's worth. We'd rather use that money to go on another cruise - if the cruise lines ever start back up.
I started out working with the old brick. Kinda wish I still had it for older vehicles.
great diag !
I generally check boosters with a vacum pump if i suspect a leak. You may want to try that for shits n giggles and see what results you get with that. Good video on working on older cars and trying to diagnose the real problems. To many hands and to many bad parts. Congrats on getting that brick, been looking at them to work on my older truck, still pretty spendy.
Dont boosters have a one way valve to hold the vacuum? Maybe this would block the smoke machine, Good to know
Hvac systems that have a vacuum reservoir will also have check valves. You can still use a smoke machine, but need to either bypass the valve, or simply change where you inject the smoke. Surprised this car didn't have a high brake effort complaint.
100%! That would have been the first clue.
The vacuum check valve won't let air flow go towards the booster.
Valve was removed.
The heater core on this year Corvette is a pain to replace. If you take out the passenger seat put a board down and then work on your back below the dash you can change it without pulling the whole dash.
The ignition distributor manifold cover plate is held in place by three small Torx head machine screws. They are usually very easy to remove but not always, and you will shear them off if you are not careful, like the screw missing in the video, which is probably sheared off. Often you have to add a little heat and get the screw to back off a turn or two, then add penetrating oil, let soak in and work the screw in and out while adding heat and more penetrating oil to free it up. The steel machine screw is mounted using machine threads directly in the aluminum manifold body without an insert or Heli-Coil, and as a result will be an excellent heat sink so adding heat you have to be careful to not add too much but also not to add too little. Once you free up the screw, and add WD40 it is easy to install. With the cover off, add WD40 to the threads and run the screws in and out a few times and the threads will lube up and the screw will not seize again.
The MAF should be a Bosch OEM replacement.
The fuel injectors do not look like OEM replacements. The original injectors on this year Corvette will tend to fail when hot. So, if one fails, it is best to replace all the injectors with a matched flow set. All of the rebuilt or new sets that I have installed on C4s 85 to 89 Corvettes have a dark body like matt black, maybe a very dark blue. As stated in the video it is relatively easy to spot the bad injector using the current clamp because it will look purely resistive and different from the other injectors. But, you have make sure you let them get very hot. So, before doing this test close the hood and let the idle until the cooling fan cycles a few times, then open the hood and do the test. You will hear the misfire most of the time as the car warms up. However, in the end you don't really narrow it down to which injector you just replace the whole set.
@@windward2818 did you watch the video or assume I didn't know? Lol
@@JoesAutoElectric Yes, I watched the complete video, and yes I assume that you know how to do the repairs. However, there are a lot of details not covered, which is okay based on the keeping the video concise. My comment was meant to give a little more detail on what I have experienced with the repairs. This is after all a very old car. Do you see any issues with my suggestions?
booster has one way check valve which does not allow smoke in when testing
True, but as I've answered in other comments...I had the valve removed.
The old bricks. Still use for them!
Hi Joe nice video. Can you tell me what drivability problems the worn steering knuckle is causing on this vette if any that you know of? Thanks
The Vette has both a frozen joint and damaged rack. Turning is the issue. Locking up and such.
You know what...even though I've got a new Snap-On Solus Legend scanner I still have my OG MTG-2500, the graphing brick and all the adapters n stuff for old OBD1 stuff. Works wonders sometimes even though I have the adapter to use all those old adapters on the Solus Legend, the old Brick can still talk to some older stuff the Legend can't. Still something useful to have the diagnostic arsenal.
when you get a leaking heater core like that, just bypass it so you can go on diagnosing :)
Heater cores are a pain no matter what car you're dealing with. Usually you have to take most of the dash out to get to them.
good job
Thank you! Cheers!
What was wrong with the explorer with the issue caused by the dealer?
The Strap-on prick is the fastest OBDll code retriever I’ve used
Great vid Joe. Pinching off that booster line was key. No. Knowing the fuel trim of that polder system. Did u get to use the MT 2500? Thanx for sharing your experience with us!!
Yes sir. That scan tool works great and is like brand new. It was a great help for this old Vette.
Was the Brake pedal hard with that cracked servo
No sir.
Real nice case study! Thats why I subscribed.
Just went over all this with my cousin a couple of days ago. He changed the cat's and o2's and MAF and I was telling him about o2's and fuel trims and what not, I think he's been wasting money and possibly adding more problems unfortunately.
All too common, unfortunately.
Another thing the tpi motors like to kill are the temperature sensors. Messes with so many things when they fail.
Anytime an ect failure occurs on fuel injected engines, there will be problems.
Hi Joe, how do you check fuel trims and air flow on an obd1 system ? Excellent video as always. Keep up the great work and content.
Scan tool that can communicate and get data
THE BRICK! my brother has one!
I'm so glad my 90 TPI car is a speed density system, no MAF for me. These are such simple systems, but can be really frustrating if you can't see all the ECM data because they are only OBD1. Moates makes the cable you need, if you have one of these. Tuner Pro is the software you want.
These engines have junk fuel injectors that gradually short out and cause the engine to shutdown suddenly with no diagnostic code. Bosch makes some that will fit the rails and connectors.
Having worked on TPI Corvettes I knew you had a vacuum leak
lol
The check valve at the booster will not allow pressure through, its one way,, so no surprise you didn't see smoke there. If you had you'd have a bad booster and check valve.....
With check valve removed it was not visible either.
THE BRICK!!!!
That blue oval on your shirt means you've seen some bizarre mixtures of American, Asian, and European automotive technology. That spells _experience,_ and _ability_ to diagnose. That means you are the proper technician to addresss issues on any bizarre combination of all of the above, be it GM, Ford, Dodge, Mazda, Honda, Toyota, MCB, or Bimmer.
That is why I like you.
Masters that can stand back and decipher (seriously) stupid shit like this deserve the salutes you unfortunately never receive.
You are the kind of guy I wish I could send my (parts store) customers to.
You the man Joe nice! What year was that Vette?
It is an '88.
The average mechanics I know would've gave up. His inspection skills are superb.
Thank you sir. I am just trying to fix stuff is all.
Sh!!!!!!!t I love learning old school testing!!
Good God, a plastic brake booster? I've never seen that before. I do hate working on Corvettes
I have only worked on a handful over the years. They are just a pain man. No room to do anything.
That's the problem dealerships don't want to pay diagnostic X
Dude shoulda brought it to you along time ago
Dang Joe!! I wish you were in the SF Bay. I would try and become a customer of yours!! In my business, I send 2-3 cars per week to the shop and most of these guys only want to do brakes. They really do not want to troubleshoot problems. Talent & skill like yours is a lost art. You gained a sub!
Thanks for te support
when you are watching a video and all you think of is... are you gonna smoke that sigaret or not? lol
and then.. finally.
They last longer that way 😂
Plastic parts and aluminium parts are cheap to produce & lightweight. But, they disintegrate by themselves so quickly..
Great job on this one..... Always tough to start over after 3 people have looked at it.... Ugh. I'm in a different industry, but we get that too... then you spend all day wondering, was it like that?? Or did somebody do this, thinking it would help? What is going on here?? This can't be the way it was originally, right???? Gives me a headache just thinking about it....
You remind me a lot of one of my friends... He can fix anything, as long as he doesn't run out of smokes... Heh heh! Just kidding Sir. No, how he reminds me of you is, he might look a little rough around the edges, but he is a genius on cars, especially Japanese stuff... Toyota & Nissan, he's a walking encyclopedia.... An Encyclopedia that needs a steady diet of coffee and Marlboro Lights to keep functioning at a high level....
That's awesome man. I never look at the time here. I just tell my partner, It's out of smokes O'clock, so I have to go.
Nice OBD1 scanner, I wish I had friends like you. Question..is there a way to use a laptop to read OBD1? Right now if the money lights up, I`m jumping the port to read flashes caveman style...lol
Not that I know of
How many curse words were you using?? And did you invent any new ones while working on the corvette??
That can be an entire video of its own.
They would’ve the break. Brake booster
Can you fix my c4 now 😂😂
Sure
Joe's Auto Electric lol just kidding I can’t afford to fix it
I bet it was a school teacher who last touched those bolts.
Why a school teacher?
@@JoesAutoElectricWell it's been over my 40 years in the business that teachers are
n't the most mech. inclined. sorry teachers just what i observed.
Sorry dude, live to learn about my 93 c4, but the Marlboro juggling is driving me crazy. Good day mate
Well, if that bothers you, you have way bigger problems than my video.
👍👍
Band
Basically good tutorial Joe. Try to make less "conversational" and more directed at subject matter.
Thanks, but I do things my way for a reason.
you would think smoke would have been pouring out that plastic booster! spectra mass air ?? what? well theres a seat for every ass! next job.... an opti i think in 87 they went multiport what a big improvement