When I was a GM mechanic the dielectric grease was for the heat sink between the moduel and the mounting surface to pull away heat generated by the moduel .Just FYI.
Great to see the circuit diagram and the details of the following procedure explained.The scope gives a good visual of what is happening in real time as well as being able to record and manipulate the signal such as the coil pickup voltage.Keep up the good work.
Lots of comments about the dielectric grease. When I did TV work, a 100 years ago :) it was always used on the "HOT" - Horizontal Output Transistor. A metal unit with a Mica insulator to hold the case above system ground. But, the grease was definitely used to help transfer the Trans Heat to the Heat Sink to which is was mounted. Thanks Ivan - am a great fan of you and Eric. Go New York!
Hey Ivan great video and diagnosis! Been a long, long time sense I have seen a TBI. Actually brought a smile to my face. Brings back a lot of old memories. I use to own a '94 C1500 with a weak sauce 4.3 and a 5 speed. Me and Vanessa meet when I had that hot rod lol.
+South Main Auto Repair Weak sauce LOL. They were not a bad motor in the s-10's but ya, in a 1/2 ton you always had to push it too the wood. When is the S-10 coming back for the transfer case install?
Brought a smile to you, but brought a tear to me. Last summer, I put an 87 model 305 in a 69 4x4 short bed Chevy p/u. Was a nightmare. Went to a carb, had to order an edelbrock manifold! Got exhaust manifolds off, replaced some bolts and gaskets, then the manifolds wouldn't go back on! Luckily, we had a couple sets laying around to choose from. Put an auto/overdrive behind it. That was a chore. Then the wiring harness was trash, so I had to rehab that. New homemade from the dash to the tail/turn/stop lights! Rust falling in my face the whole time! SAFETY GLASSES, REQUIRED!! However, the best part of the whole ordeal??? I didn't have to use a jack/jack stands not once!! It was tall enough for me to get under it without jacking it up!! PRICELESS!! I just deflated the front tires, to get the engine in and out!!
Thank you for this video! My dad's 92 Chevy died going down the road. It would crank, but wouldn't start. No fire at the ignition coil. Replaced coil, still no spark. your video saved us a towing fee to a mechanic shop because we were stumped. Replaced the ignition coil module and it fired right up! Thanks again for putting this information out there!!!
You are exactly right with that one ivan. Dielectric grease/ bulb grease is for keeping out moisture and debris from electrical connections. 👍and makes no difference on conductivity other than keeping contact points clean so they can pass juice well.
Good video Ivan thank you for sharing it. I remember my 84 Ford Mustang with the thick film ignition same problem. I replace the module one time without the dielectric grease and had to replace it again shortly thereafter. That's the beautiful thing about working on vehicles they teach us lessons all the time. The only thing that matters is that we learn something and move forward. Thank you for making these videos and for the hours of video editing.
My friend, whose life depends on having his vehicle, (1990 Suburban), had the exact symptoms you described in your video. We replaced coil, no luck, (we determined there was fuel, but, no spark) , replaced ignition module, and, lo and behold, no tow truck, no mechanic, no 400.00 bill. 58.00 total, and he was back on the road, with, all his life's possesions. Thankyou, thankyou, thankyou
I have a tip. On Chevy Silverados after you have been driving on snow covered roads on your way to work during the winter. After you get off work the starter won't crank. What happens is the drain hole in the starter housing gets snow and water packed up there into the starter gears. It then freezes and won't let the starter turn over. You need to go under the pickup with a little benzomatic propane torch and warm up the starter to melt the ice. After that I put a dab of door and window caulking over that hole and have had no issues with my pickup starting for the last 4 years now.
I use dielectric grease on connections, but also on the mating surface of the module. It helps dissipate the heat. Great video. Funny ending with owner revving engine and then running away! (Also works on the ceramic part of spark plugs that contact plug boot)
Hey Ivan, good video,,, FYI what is in the squeeze tube is actually heat sink compound to be applied to the shiny surface of the module where it contacts the distributor base which acts as a heat sink. It is to conduct the heat from the module to keep it from overheating and burning out.
Enjoyed this video.. reminds me of when I went through 6 control modules in my '79 Chevy Blazer before I landed on one that wasn't screwed up in manufacturing.. you probably know that problem more than most.... thanks for all of the useful info you provide your viewers.. (me)(etc.)...
I had the exact same thing happen on my '95 C1500...driving to work and she just quit. I could hear the fuel pump so I threw in an ignition control module and the 4.3 fired right up. Now I carry a spare and a long phillips behind the seat. The '88 to '98 chevys turned out to be damn good trucks. Unlike the '99 and newer Chevys the rocker panels actually made it home from the dealer without rust holes!
+cbsctomh Agreed the sheet metal seems to be higher quality on the older 90s trucks. My neighbor has a 99 Tahoe and a '05 Yukon. The newer Yukon already had rockers replaced!! The 99 is still going strong at 225k...like a rock lol
Awesome Video! Thanks for sharing all of your videos. I watch and re-watch them . So much knowledge in here - my brain is too small. Watching you go through these troubleshooting steps is like watching a brain surgeon at work. Amazing stuff !!
I remember in the alignment video you mentioned about your grandfather. that's how I got my start because my grandparents owned a farm in upstate New York.
Man, your vdo is the best bro. Thanks so much for posting. I looked all over TH-cam and tried many different ways to fix my early '90 gmc van with no start when engine is hot. Not much luck. Fortunately; I came across your vdo today and decided to replace the ignition module. Cost me $31@ oreilly and boom, the old van run like a champ now😁👏🏼👏🏼👏🏼. Thanks again keep up the good work.
Nice work Ivan on the diagnostics. I'm with most viewers about the grease, but I would use a thermal grease which improves the heat conductivity of the module. I remember that Radio Shack sold thermal grease as I used it on controllers for sodium lighting systems years ago. They may still sell it, not sure. The dielectric grease I would just use on the electrical connectors.
1993, C1500, 5.7l. OBD-I flashy blinky code said there was a problem with the ignition module. I pulled the ignition module and took it to O'Reilly. They had an ignition module tester at the store. Although, only the long-time employee knew how to use the thing! My module tested bad. I also had them verify the new replacement module checked out okay *before* I left the store. No muss, no fuss. Nice to have repair issues go so smoothly!
At the end your video: That ISN'T dielectric grease for the terminals. That's HEAT TRANSFER grease, that spreads onto the entire metal side of that module. It transfers heat from the module to the more heat-tolerant distributor. Just a little tip for the rest of you watching this.
Also when replacing the coil pack it has two pins pressed in to hold it to the bracket instead of drilling I used two good punches and was able to punch the pins right out in one or two minutes instead of drilling it out. I spray it with PB Blaster or WD-40 and then start the punch and give it another quick spray half way through and the pins will just start to fall apart and it'll come right out of the bracket. I did have a drill ready if I needed it but the punch and a hammer did the trick. Just a tip to anyone looking for ways to get those "rivet pins" out. Good Luck.
It's nice to take a little trip back to a more simple time when diagnosis was easier than today. I used to get right up inside of them like you suggested. The dielectric grease was supplied for the back of the module. I never questioned the reason as G.M. requested that it be applied there but I always assumed it was for heat transfer. Maybe it should be there to insulate it from the hot distributor base ?? I dunno. Something else I learned on those is the little screened holes in the base of the distributor are there for air circulation inside the distributor to allow electrical gasses to escape. If they got plugged the distributor cap contacts (Aluminum) would oxidize in a short period time. I also noticed that the plug had been removed from the pick-up coil to the module.
Enjoyed the scientific approach!! The dielectric grease is mostly to smear on bottom of module to assist in heat transfer. Your Verus doesn't seem to act up like Eric's. Maybe the torch and brake clean have something to do with it
+Bill Rimmer Thanks Bill! I'm curious how hot that ICM can actually get on its own under normal operation. It's only passing maybe 5 amps during running with minimal resistance. The distributor itself doesn't live in the most cool location either. Wonder why they didn't just mount it to the firewall or something if heat was such a big concern!
Great video. Love your scanner. Almost my situation with my dads truck which was running great after a fuel pump replacement for a few days then the real issues started. Truck died in town and towed back. The engine will start and run on its own only with the spout connector disconnected and only up to about 2000k on the tach and no higher like its limited, but spit hell and fire with the spout connector connected and will not not start on its own without some coaxing. Parts list has grown to New cap, rotor, wires, spark plugs, spark control module, map sensor, fuel pump, 2 wire temp sensor, throttle position Base timing is confirmed set to 0 with spout connector disconnected. Codes are 33-MAP signal voltage low, 42-Ignition control circuit(shorted circuit), 54-Fuel Pump relay voltage low. What I would like to know is the PCM the culprit now at this point and wouldnt that throw a code 55-PCM failure? i get 12v at the power leads at the PCM plugs and grounds at the ground wires. Without an advance scanner(ill own one someday!) im helpless at this point... Any help or ideas would be appreciated.
It has been my experience that with a scan tool plugged in, if the module is bad, the ECM should still see a crank RPM signal, fire the injectors once or twice, then stop, if the pick up coil is good. You should've stuck a noid light on it also while checking for spark. If the ECM loses its ability to control timing, it should start and run at base time off the module at fixed 0*, which was also common. That style HEI coil rarely goes bad. The older style coil in cap design did from time to time. Also worth noting, if you have a low battery, or the starter is drawing too much, the truck will not fire the injectors nor spark, until the ECM sees at least 150-200 rpm. Oh, and the noise you heard was the fuel pump prime.
IVE BEEN WORKING ON MY TRUCK FOR ABOUT 6 MONTHS MOSTLY DUE TO LACK OF FUNDS.LONG STORY SHORT THIS IS THE BEST VIDEO IVE WATCHED ON THIS SUBJECT IT WAS SHORT AND SWEET...I GOT MORE INFORMATION AND IT TACKLED THE ISSUE.GIVING SOLUTIONS TO MORE THEN ONE PROBLEM
🔥 video... I’m having this same issue on my 88 obs 350 v8 as of yesterday 11/3/23 makes me want to just order this part and try it out I pray it works but I know there’s a few other parts it could be as well I have to check first ignition module, control module, pick up coil, map sensor, or fuel pump I pray it’s a cheap fix $50-$150. I don’t want to just throw parts at it. I don’t like to fix things that aren’t broken as my grandfather would say.
_Most_ of my experience is with "older" GM. That aluminum plate used to be (and still is AFAIK) referred to as the "Breaker Plate" (it was where the points/condenser were). With HEI systems it must be bright, shiny clean- and that dielectric grease is applied to the mating surface of the module-to-breaker plate to dissipate heat (the breaker plate is a heat sink). That magnet and reluctor ring is very rusty, and that will cause a weak (but still useable) signal. I feel very sorry for that neglected engine- dirty, oily, covered with debris, loose throttle body, etc. A clean engine runs cooler- and the ignition being situated in the rear is a heat magnet, for sure. Standard motor Products T Series are very quality parts for the price. Do some research before you condemn.
I had a 96 Chevy 1500 truck 4x4 5.7 V-8... crank no start it would kind of shudder or slightly start but not run smooth then just crank but would not start. Replaced the cap and rotor along with ignition coil pack and it started right up and runs great now. I didn't just throw parts at it though i did about 2 hours of checking fuel pump, fuel relay, pressure at fuel rail and it all checked out. Next tested spark it was there but faint or weak not much flash in my tool tester. Pulled the cap and rotor and had a burn hole in the rotor so I knew I was on the right track. Replaced ignition coil and cap and rotor and its fixed. Hope this helps someone with my symptoms!!
Your comment on the grease was spot on. There is a heat sink grease but, that's different. The grease you applied is for corrosion purposes, The terminals will scrape together just enough make the electrical contact. Don't get carried away using it. I be an EE for thirty years and it was widely used in the telephone company's battery plant. No corrosion there.
Nope that grease is actually a silicone and it’s meat to go under the module on medal part so it protects it from heat. If he read the paper that was inside it would have explained that.
My dad had an '89 (the year before I was born) very similar to this truck, same color even, and claimed that noise in the passenger footwell had to do with the heater. But he's not exactly a mechanic and I learned he tends to make stuff up to not look dumb in front of his son, so I don't really know. I loved that truck, and she still rarely wanders the town with the new owner, but Dad apparently fried the gears hauling a camper over a mountain in overdrive 5 years or so ago.
I always use the grease under the control module . I agree with you on the grease , it is not conductive , that is y it is used , it maintains the connection and also like i insulator to protect the connection . Good job
+wtbm123 Huh I've never had to install one of these so I just guessed where the grease went lol :) So what exactly is the purpose of the grease on the bottom of the module?
So in operation the module must heat up MORE than the distributor base, if that's the designed direction of heat flow (module to distributor base). I am tempted to drive around with a thermocouple taped to the dizzy on my '89 MPV to see how hot that sucker gets. All I know is that it burns up the internal igniter about every 10 years/100k miles...
Stabilant 22A is a liquid that increases conduction. NAPA sells it. Silicone grease is used to help the heat transfer to heat sink. Used on other hot electronic components. Good show! Thanks.
The Dielectric grease is supposed to go on the bottom of the ignition module to keep it cool because it gets so hot. The heat is what destroys those ignition modules. So the Dielectric grease goes on the shiny metal flat surface on the bottom.
The noise you heard was the fuel pump activating, and make sure you use thermal grease on the metal plate on the ignition module or you will burn it out. It has to use a heat sink to protect the circuit components inside the module, in this case the metal shelf it is attached to on the distributor. Thermal or heat sink grease is white in color. Dieletric grease is good for connectors but it is not a heat sink grease, heat sink grease conducts heat from the part to the heat sink to prevent the semiconductor from burning out inside the module, it is thermally conductive. Think computer chip, like your processor in your computer needs to conduct heat out and away to protect it, we use heat sink compound or grease to do this with the heat sink being a metal processor cooler of some type, the ignition module is sort of like a small computer in that it takes inputs and creates an output, in this case a timed signal to initiate the spark on each cylinder. It creatse heat and heat destroys electronic connections inside the semiconductor so you have to transfer the heat away, and that is what the thermal grease and metal plate on the distributor does.
Those TBI engines are so easy to repair compared to today's engines. To pull codes, all you need is a jumper between the A and B terminals on the DLC and off to work finding the problem.
Had ignition module fail in mine, no fire. Had choices of modules from different manufacturers and price. I chose a AC Delco from Rock Auto and installed when parts arrived. I also did complete ignition tuneup with cap rotor, wires, plugs and chose AC Delco for quality and longevity. Upon start up, I had a smooth running engine and all was well until traveling on road test for about ten miles and engine stalled, left me stranded on roadside with a no start again. So much for AC Delco quality on the module as it failed at ten miles!
I was surprised to hear a scary buzzer when you opened the door of this 1988 Chevy Silverado. I thought the redesigned Silverado from 1988 only used the electronic chime tones.
Just to add to the diagnostic I have the same system on my 87 Silverado same problem. No spark or injector control I ready did all the test the pick up coil test past the same as Ivan's video. The problem was not the module the pickup coil only worked when disconnected from module but when I back probe and connect to module no signal. So the problem ended up being PU coil. So make sure you test with PU coil connected to module so you do not replace for no reason and confirm PU coil. I did all test on bench was easier just power coil and ground Dist base connect 2 harness to coil and Dist ground test light then tip to coil if you get spark all good. If in the the vehicle no spark check wiring to ECM.
I knew since the very beginning it was the ignition module, it is a very common failure on this model. That's a happy customer! Thank you Ivan! For the guys with the dilemma about the Dielectric grease and the thermal compound: That grease is for the connectors. You never put dielectric grease as a thermal compound. Thermal compound is used between the module and the mounting surface whenever there is a cooling aluminum heatsink outside the ignition enclosure but in this case that chevy does not have a aluminum heat sink for the module in there so no thermal compound is needed. That ignition body is way hotter than the module and cannot dissipate the heat in the module. In fact module failure due to engine heat is a common issue in this truck. (Engine is hotter than the module)
Use to be Ignition modules in these trucks is what kept the parts guys paychecks coming. Hard to believe there's still one of these with that low mileage.If that clock still worked.
this old car didnt need a oscilloscope and all that. you simply check the input and output on the module for resistance. resistance too high the thing is kaput.
Super Godzilla that was ford techs and thick film ignition or TFI as it was affectionately called. Modules burned so fast every guy had one in his tool box and the special socket to UN bolt it.
The picture that I sent is of a similar module in a 02 5.7 gmc 3500 van. That aluminum heat sink is just for that module. Hope we will get u and Eric to review the Maxi Das. Thanks again!!
+Bill Rimmer Wow so GM finally had the sense to get that module out of the hot distributor for a breath of fresh air and mount it to a proper heatsink?! Cool! Do you want to see an overview of my older MaxiDas708 or Eric's fancy wireless MaxiSys tablet?
+motoYam. The wireless one Eric has would b neat but if the older one one will do the bidirectional stuff, that's what I am looking for. Some of the comments I have read on Amazon say that the ones they sell r gray market and r difficult to register. Did u buy yours new?
those modules slowly wear out over time..the heat gets to them. always make sure you apply that heat grease on the underside when you install the new one.my astro van always idled rough and didnt have as much power as tit should..new module solved everything.
Back when I had a vehicle with this ignition I was advised to carry a spare module in the glovebox. They were known to leave dead vehicles on the side of the road.
Nice diagnositcs. Beats the other method - throw parts at it... My truck is shutting off while driving! It won't start until I turn the key off then back on. I'll use this video to diagnose - although I don't have scope. Shade tree here....
He’s exactly right about the dielectric grease. It is not to be put on the module itself, just the connectors. Heatsink compound is used on transistors to help with heat dissipation. It’s white and somewhat sticky. Just a little tiny bit will go everywhere it’s not wanted. Lol
I would have also replaced the pickup coil as well. Only problem is the distributor has to be removed and disassembled to access the pickup coil. Takes longer but worth the extra time and money in my opinion.
A dielectric (or dielectric material) is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material as they do in an electrical conductor but only slightly shift from their average equilibrium positions causing dielectric polarization. Because of dielectric polarization, positive charges are displaced in the direction of the field and negative charges shift in the direction opposite to the field (for example, if the field is moving in the positive x-axis, the negative charges will shift in the negative x-axis). This creates an internal electric field that reduces the overall field within the dielectric itself. If a dielectric is composed of weakly bonded molecules, those molecules not only become polarized, but also reorient so that their symmetry axes align to the field.
Spark control/ distributor control module had the same issue with my 92 s10 with the tbi 2.8 was scratching my head. My step dad and grand pa both asked if i had replaced the icm and i was like what and thats when they told me yeah inside the distributor cap.
This video looks like great info right away. Hopefully it helps. Similar thing in my sierra i use to and from for work. Fingers crossed. Cant afford to throw money at it
New engine, started right up. Was running. 1994 chevy c2500 now no spark. New plugs, 2 sets wires, 2 caps, 2 rotor, 2 coils, 2 ditributers, fuses, 2 modules...coil sparks once on key power up make/break. No spark at plugs....
Older HEI distributors, especially those with the coil in cap design, had the module mounted internally beneath the rotor. The dielectric grease was mostly used to to aid heat transfer between the module and the mounting surface. Forget to put some on and the module overheats and fails again in short order.
Good job there I have to buy this diagnostic tool then I have to learn to identify all the engine components and all the accessories in vehicles it will take a while.
That noise was the electric fuel pump, you didn't know that? Also, dielectric grease keeps oxidation down to due to isolating the metal from oxygen, and I think you needed to apply thermal paste to the bottom for proper heat transfer to keep the module from overheating.
that noise was a electric motor under the dash for the air and heat that I know for a fact. Just letting u know. I have an 89 silverado and mine does it. Ive only seen it on the 88 and 89 chevy trucks. my brother has a 90 and it doesnt do it on his
Dielectric grease is not recommended for the bottom of the module. Go to Radio Shack or a computer parts store and get heat sink paiste. It is designed to transfer heat, way better than dielectric grease. I bought a big tube of it off of Amazon. Within a year I've had 2 ignition modules go bad. And I don't buy the cheap ones either.
the included grease goes under the module for heat protection from the engine. Without it module will fail its not for terminals. If you read the directions they most likely stated that as well
I agree with everything Bob Weiss wrote in his message 32 minutes ago, which begins:"It is definitely going to get hot".The power transistors usually have about 700 millivolts drop across them, and they are NOT very efficient. It is a PN semiconductor junction.
When I was a GM mechanic the dielectric grease was for the heat sink between the moduel and the mounting surface to pull away heat generated by the moduel .Just FYI.
yep
Glad you said something, because that is how I remembered it as well. Not even sure it was dielectric grease but thermal compound.
Shain Andrews yes, needs grease for heat sink
I do agree with dielectric grease for sure.
Dielectric grease is mandatory for sure
Ivan you are a great diagnostic guy. Being so young, you have a great understanding of electrical engineering. Great videos
Great to see the circuit diagram and the details of the following procedure explained.The scope gives a good visual of what is happening in real time as well as being able to record and manipulate the signal such as the coil pickup voltage.Keep up the good work.
I had the same problem on my 89 GMC Jimmy, replacing the icm solved my issue too. Thanks for making this video, it was very helpful.
Lots of comments about the dielectric grease. When I did TV work, a 100 years ago :) it was always used on the "HOT" - Horizontal Output Transistor. A metal unit with a Mica insulator to hold the case above system ground. But, the grease was definitely used to help transfer the Trans Heat to the Heat Sink to which is was mounted. Thanks Ivan - am a great fan of you and Eric. Go New York!
You are a wiz with the electrical!!
Love learning watching you at work.
👍👍
Hey Ivan great video and diagnosis! Been a long, long time sense I have seen a TBI. Actually brought a smile to my face. Brings back a lot of old memories. I use to own a '94 C1500 with a weak sauce 4.3 and a 5 speed. Me and Vanessa meet when I had that hot rod lol.
+South Main Auto Repair Weak sauce LOL. They were not a bad motor in the s-10's but ya, in a 1/2 ton you always had to push it too the wood. When is the S-10 coming back for the transfer case install?
Brought a smile to you, but brought a tear to me. Last summer, I put an 87 model 305 in a 69 4x4 short bed Chevy p/u. Was a nightmare. Went to a carb, had to order an edelbrock manifold! Got exhaust manifolds off, replaced some bolts and gaskets, then the manifolds wouldn't go back on! Luckily, we had a couple sets laying around to choose from. Put an auto/overdrive behind it. That was a chore. Then the wiring harness was trash, so I had to rehab that. New homemade from the dash to the tail/turn/stop lights! Rust falling in my face the whole time! SAFETY GLASSES, REQUIRED!! However, the best part of the whole ordeal??? I didn't have to use a jack/jack stands not once!! It was tall enough for me to get under it without jacking it up!! PRICELESS!! I just deflated the front tires, to get the engine in and out!!
TBI was the best fuel delivery system ever made. Simple, easy and cheap to fix and maintain as well as being extremely reliable and rugged.
quite a bit more reliable than the poppet valve spider injection..
jewllake I drive a 1994 Chevy k1500 350 TBI and a 5speed. Great shape and you can't kill the tbi 350s
Thank you for this video! My dad's 92 Chevy died going down the road. It would crank, but wouldn't start. No fire at the ignition coil. Replaced coil, still no spark. your video saved us a towing fee to a mechanic shop because we were stumped. Replaced the ignition coil module and it fired right up! Thanks again for putting this information out there!!!
Heat sink must be used..😂
Great vid, got me back up and running just by watching and learning. I had the exact same symptoms and cause.
You are exactly right with that one ivan. Dielectric grease/ bulb grease is for keeping out moisture and debris from electrical connections. 👍and makes no difference on conductivity other than keeping contact points clean so they can pass juice well.
I've got a 93 Caprice with this TBI still on the road. 309k miles. Runs great.
Good video Ivan thank you for sharing it.
I remember my 84 Ford Mustang with the thick film ignition same problem. I replace the module one time without the dielectric grease and had to replace it again shortly thereafter. That's the beautiful thing about working on vehicles they teach us lessons all the time. The only thing that matters is that we learn something and move forward. Thank you for making these videos and for the hours of video editing.
DaveSender66 If the timing mark flutters, it's the module. Ford had a recall on those modules.
Another solid fix! The owner cracked me up. All into it once it was running.
My friend, whose life depends on having his vehicle, (1990 Suburban), had the exact symptoms you described in your video. We replaced coil, no luck, (we determined there was fuel, but, no spark) , replaced ignition module, and, lo and behold, no tow truck, no mechanic, no 400.00 bill. 58.00 total, and he was back on the road, with, all his life's possesions. Thankyou, thankyou, thankyou
I don't know why but I really got a chuckle out of the owner running up and stabbing the throttle a few times then shutting it off.
yes...and before the alt had ample time to even throw a surface charge to the battery
Probably embarrassed that Ivan fixed it after he shot the parts cannon at it.... :)
Must've had a near empty fuel tank and didn't want to waste a drop... He sure was in a hurry to switch it off.
Yep, he’s got places to go...
I have a tip. On Chevy Silverados after you have been driving on snow covered roads on your way to work during the winter. After you get off work the starter won't crank. What happens is the drain hole in the starter housing gets snow and water packed up there into the starter gears. It then freezes and won't let the starter turn over. You need to go under the pickup with a little benzomatic propane torch and warm up the starter to melt the ice. After that I put a dab of door and window caulking over that hole and have had no issues with my pickup starting for the last 4 years now.
I use dielectric grease on connections, but also on the mating surface of the module. It helps dissipate the heat. Great video. Funny ending with owner revving engine and then running away! (Also works on the ceramic part of spark plugs that contact plug boot)
Hey Ivan, good video,,, FYI what is in the squeeze tube is actually heat sink compound to be applied to the shiny surface of the module where it contacts the distributor base which acts as a heat sink. It is to conduct the heat from the module to keep it from overheating and burning out.
That stuff transfers heat better than "dielectric grease" it's not the same stuff for anyone who doesn't know.
Enjoyed this video.. reminds me of when I went through 6 control modules in my '79 Chevy Blazer before I landed on one that wasn't screwed up in manufacturing.. you probably know that problem more than most.... thanks for all of the useful info you provide your viewers.. (me)(etc.)...
6 modules bad, man I would of gone crazy trying to get that thing started..
I had the exact same thing happen on my '95 C1500...driving to work and she just quit. I could hear the fuel pump so I threw in an ignition control module and the 4.3 fired right up. Now I carry a spare and a long phillips behind the seat. The '88 to '98 chevys turned out to be damn good trucks. Unlike the '99 and newer Chevys the rocker panels actually made it home from the dealer without rust holes!
+cbsctomh Agreed the sheet metal seems to be higher quality on the older 90s trucks. My neighbor has a 99 Tahoe and a '05 Yukon. The newer Yukon already had rockers replaced!! The 99 is still going strong at 225k...like a rock lol
Awesome Video! Thanks for sharing all of your videos. I watch and re-watch them . So much knowledge in here - my brain is too small. Watching you go through these troubleshooting steps is like watching a brain surgeon at work. Amazing stuff !!
I remember in the alignment video you mentioned about your grandfather. that's how I got my start because my grandparents owned a farm in upstate New York.
Man, your vdo is the best bro. Thanks so much for posting. I looked all over TH-cam and tried many different ways to fix my early '90 gmc van with no start when engine is hot. Not much luck. Fortunately; I came across your vdo today and decided to replace the ignition module. Cost me $31@ oreilly and boom, the old van run like a champ now😁👏🏼👏🏼👏🏼. Thanks again keep up the good work.
Awesome!
Nice work Ivan on the diagnostics. I'm with most viewers about the grease, but I would use a thermal grease which improves the heat conductivity of the module. I remember that Radio Shack sold thermal grease as I used it on controllers for sodium lighting systems years ago. They may still sell it, not sure. The dielectric grease I would just use on the electrical connectors.
Another great vid, Sir! Thanks for the share! Time to get Eric the O guy up for an assist! You're two up on him.
1993, C1500, 5.7l. OBD-I flashy blinky code said there was a problem with the ignition module.
I pulled the ignition module and took it to O'Reilly. They had an ignition module tester at the store. Although, only the long-time employee knew how to use the thing!
My module tested bad. I also had them verify the new replacement module checked out okay *before* I left the store.
No muss, no fuss.
Nice to have repair issues go so smoothly!
At the end your video: That ISN'T dielectric grease for the terminals. That's HEAT TRANSFER grease, that spreads onto the entire metal side of that module. It transfers heat from the module to the more heat-tolerant distributor. Just a little tip for the rest of you watching this.
Cool old school diag. I seen many broken wires from heat on the pick up coil pole piece.
I think it is cool how you and Eric work as a team and help each other out!
Also when replacing the coil pack it has two pins pressed in to hold it to the bracket instead of drilling I used two good punches and was able to punch the pins right out in one or two minutes instead of drilling it out. I spray it with PB Blaster or WD-40 and then start the punch and give it another quick spray half way through and the pins will just start to fall apart and it'll come right out of the bracket. I did have a drill ready if I needed it but the punch and a hammer did the trick. Just a tip to anyone looking for ways to get those "rivet pins" out. Good Luck.
It's nice to take a little trip back to a more simple time when diagnosis was easier than today. I used to get right up inside of them like you suggested. The dielectric grease was supplied for the back of the module. I never questioned the reason as G.M. requested that it be applied there but I always assumed it was for heat transfer. Maybe it should be there to insulate it from the hot distributor base ?? I dunno. Something else I learned on those is the little screened holes in the base of the distributor are there for air circulation inside the distributor to allow electrical gasses to escape. If they got plugged the distributor cap contacts (Aluminum) would oxidize in a short period time. I also noticed that the plug had been removed from the pick-up coil to the module.
Enjoyed the scientific approach!! The dielectric grease is mostly to smear on bottom of module to assist in heat transfer. Your Verus doesn't seem to act up like Eric's. Maybe the torch and brake clean have something to do with it
+Bill Rimmer Thanks Bill! I'm curious how hot that ICM can actually get on its own under normal operation. It's only passing maybe 5 amps during running with minimal resistance. The distributor itself doesn't live in the most cool location either. Wonder why they didn't just mount it to the firewall or something if heat was such a big concern!
Good thanks
Great video. Love your scanner. Almost my situation with my dads truck which was running great after a fuel pump replacement for a few days then the real issues started. Truck died in town and towed back. The engine will start and run on its own only with the spout connector disconnected and only up to about 2000k on the tach and no higher like its limited, but spit hell and fire with the spout connector connected and will not not start on its own without some coaxing. Parts list has grown to New cap, rotor, wires, spark plugs, spark control module, map sensor, fuel pump, 2 wire temp sensor, throttle position Base timing is confirmed set to 0 with spout connector disconnected. Codes are 33-MAP signal voltage low, 42-Ignition control circuit(shorted circuit), 54-Fuel Pump relay voltage low.
What I would like to know is the PCM the culprit now at this point and wouldnt that throw a code 55-PCM failure? i get 12v at the power leads at the PCM plugs and grounds at the ground wires. Without an advance scanner(ill own one someday!) im helpless at this point... Any help or ideas would be appreciated.
It has been my experience that with a scan tool plugged in, if the module is bad, the ECM should still see a crank RPM signal, fire the injectors once or twice, then stop, if the pick up coil is good. You should've stuck a noid light on it also while checking for spark. If the ECM loses its ability to control timing, it should start and run at base time off the module at fixed 0*, which was also common. That style HEI coil rarely goes bad. The older style coil in cap design did from time to time. Also worth noting, if you have a low battery, or the starter is drawing too much, the truck will not fire the injectors nor spark, until the ECM sees at least 150-200 rpm. Oh, and the noise you heard was the fuel pump prime.
Another great video my man! nice tests! love the bypass test, use it whenever i can.
IVE BEEN WORKING ON MY TRUCK FOR ABOUT 6 MONTHS MOSTLY DUE TO LACK OF FUNDS.LONG STORY SHORT THIS IS THE BEST VIDEO IVE WATCHED ON THIS SUBJECT IT WAS SHORT AND SWEET...I GOT MORE INFORMATION AND IT TACKLED THE ISSUE.GIVING SOLUTIONS TO MORE THEN ONE PROBLEM
Thanks!
🔥 video... I’m having this same issue on my 88 obs 350 v8 as of yesterday 11/3/23 makes me want to just order this part and try it out I pray it works but I know there’s a few other parts it could be as well I have to check first ignition module, control module, pick up coil, map sensor, or fuel pump I pray it’s a cheap fix $50-$150. I don’t want to just throw parts at it. I don’t like to fix things that aren’t broken as my grandfather would say.
Great video! Had the exact same problem with my truck. Solution was well documented, explained and worked. TY
_Most_ of my experience is with "older" GM. That aluminum plate used to be (and still is AFAIK) referred to as the "Breaker Plate" (it was where the points/condenser were). With HEI systems it must be bright, shiny clean- and that dielectric grease is applied to the mating surface of the module-to-breaker plate to dissipate heat (the breaker plate is a heat sink). That magnet and reluctor ring is very rusty, and that will cause a weak (but still useable) signal. I feel very sorry for that neglected engine- dirty, oily, covered with debris, loose throttle body, etc. A clean engine runs cooler- and the ignition being situated in the rear is a heat magnet, for sure. Standard motor Products T Series are very quality parts for the price. Do some research before you condemn.
Ignition parts by Standard, Wells and BWI are all good quality.
HUBBABUBBA DOOPYDOOP Ii
Thank you for the video you are a professional in your field!
exelente video grasias por ensenarnos no todos son como ustedes en compartir sus conosimientos
great video, I learned something new every time I watched one of your video. thank you.
I had a 96 Chevy 1500 truck 4x4 5.7 V-8... crank no start it would kind of shudder or slightly start but not run smooth then just crank but would not start. Replaced the cap and rotor along with ignition coil pack and it started right up and runs great now. I didn't just throw parts at it though i did about 2 hours of checking fuel pump, fuel relay, pressure at fuel rail and it all checked out. Next tested spark it was there but faint or weak not much flash in my tool tester. Pulled the cap and rotor and had a burn hole in the rotor so I knew I was on the right track. Replaced ignition coil and cap and rotor and its fixed. Hope this helps someone with my symptoms!!
Your comment on the grease was spot on. There is a heat sink grease but, that's different. The grease you applied is for corrosion purposes, The terminals will scrape together just enough make the electrical contact. Don't get carried away using it. I be an EE for thirty years and it was widely used in the telephone company's battery plant. No corrosion there.
Nope that grease is actually a silicone and it’s meat to go under the module on medal part so it protects it from heat. If he read the paper that was inside it would have explained that.
My dad had an '89 (the year before I was born) very similar to this truck, same color even, and claimed that noise in the passenger footwell had to do with the heater. But he's not exactly a mechanic and I learned he tends to make stuff up to not look dumb in front of his son, so I don't really know. I loved that truck, and she still rarely wanders the town with the new owner, but Dad apparently fried the gears hauling a camper over a mountain in overdrive 5 years or so ago.
That sound is indeed the blend door motors running. It is very annoying. (1988 c1500)
Great diagnosis Ivan.
you saved me alot of time!!! same exact thing happened to me and i was about to start throwing parts at it! thank you so much for this info 🙏🏻
You're a genius Ivan..Blessings.
Ivan, dielectric grease was meant to be put on the module where it mounts to the distributor before mounting to conduct heat away from the module.
Heat sink thermal paste, not dielectric grease.
It fixed my 1990 gmc sierra c1500 ive had it sitting for a month and change the part and it started right up big help appreciate you 💯
I always use the grease under the control module . I agree with you on the grease , it is not conductive , that is y it is used , it maintains the connection and also like i insulator to protect the connection . Good job
+wtbm123 Huh I've never had to install one of these so I just guessed where the grease went lol :) So what exactly is the purpose of the grease on the bottom of the module?
+motoYam82 helps seal up between the two so it does not corrode and lift .
+wtbm123 I was taught that the grease is for heat transfer from the module to the distributor base to dissipate heat from the module.
+Robert Wynkoop And it looses its heat transfer when it starts corroding under it lifting it off the plate
So in operation the module must heat up MORE than the distributor base, if that's the designed direction of heat flow (module to distributor base). I am tempted to drive around with a thermocouple taped to the dizzy on my '89 MPV to see how hot that sucker gets. All I know is that it burns up the internal igniter about every 10 years/100k miles...
Stabilant 22A is a liquid that increases conduction. NAPA sells it.
Silicone grease is used to help the heat transfer to heat sink. Used on other hot electronic components.
Good show! Thanks.
The Dielectric grease is supposed to go on the bottom of the ignition module to keep it cool because it gets so hot. The heat is what destroys those ignition modules. So the Dielectric grease goes on the shiny metal flat surface on the bottom.
The noise you heard was the fuel pump activating, and make sure you use thermal grease on the metal plate on the ignition module or you will burn it out. It has to use a heat sink to protect the circuit components inside the module, in this case the metal shelf it is attached to on the distributor. Thermal or heat sink grease is white in color. Dieletric grease is good for connectors but it is not a heat sink grease, heat sink grease conducts heat from the part to the heat sink to prevent the semiconductor from burning out inside the module, it is thermally conductive. Think computer chip, like your processor in your computer needs to conduct heat out and away to protect it, we use heat sink compound or grease to do this with the heat sink being a metal processor cooler of some type, the ignition module is sort of like a small computer in that it takes inputs and creates an output, in this case a timed signal to initiate the spark on each cylinder. It creatse heat and heat destroys electronic connections inside the semiconductor so you have to transfer the heat away, and that is what the thermal grease and metal plate on the distributor does.
Hi Ivan that grease is usually heat sink compound to put between the module and the casting to tranfer heater better....Fred UK.
Those TBI engines are so easy to repair compared to today's engines. To pull codes, all you need is a jumper between the A and B terminals on the DLC and off to work finding the problem.
Had ignition module fail in mine, no fire. Had choices of modules from different manufacturers and price. I chose a AC Delco from Rock Auto and installed when parts arrived. I also did complete ignition tuneup with cap rotor, wires, plugs and chose AC Delco for quality and longevity. Upon start up, I had a smooth running engine and all was well until traveling on road test for about ten miles and engine stalled, left me stranded on roadside with a no start again. So much for AC Delco quality on the module as it failed at ten miles!
Yup, the Chinesium eBay ones are far better. Uh-huh.
I was surprised to hear a scary buzzer when you opened the door of this 1988 Chevy Silverado. I thought the redesigned Silverado from 1988 only used the electronic chime tones.
Dude shows up after it starts lol
Just to add to the diagnostic I have the same system on my 87 Silverado same problem. No spark or injector control I ready did all the test the pick up coil test past the same as Ivan's video. The problem was not the module the pickup coil only worked when disconnected from module but when I back probe and connect to module no signal. So the problem ended up being PU coil. So make sure you test with PU coil connected to module so you do not replace for no reason and confirm PU coil. I did all test on bench was easier just power coil and ground Dist base connect 2 harness to coil and Dist ground test light then tip to coil if you get spark all good. If in the the vehicle no spark check wiring to ECM.
Driving down the road I said, this truck (same engine) always runs great. Right on cue, the good lord burned my ignition module. God, ..... was I bad?
Thanks for the upload. Helped get my 1989 GMC K2500 fixed.
That's awesome, Kevin!
I knew since the very beginning it was the ignition module, it is a very common failure on this model. That's a happy customer! Thank you Ivan!
For the guys with the dilemma about the Dielectric grease and the thermal compound: That grease is for the connectors. You never put dielectric grease as a thermal compound. Thermal compound is used between the module and the mounting surface whenever there is a cooling aluminum heatsink outside the ignition enclosure but in this case that chevy does not have a aluminum heat sink for the module in there so no thermal compound is needed. That ignition body is way hotter than the module and cannot dissipate the heat in the module. In fact module failure due to engine heat is a common issue in this truck. (Engine is hotter than the module)
Use to be Ignition modules in these trucks is what kept the parts guys paychecks coming. Hard to believe there's still one of these with that low mileage.If that clock still worked.
this old car didnt need a oscilloscope and all that. you simply check the input and output on the module for resistance. resistance too high the thing is kaput.
What Terminals do you test for resistance
Super Godzilla that was ford techs and thick film ignition or TFI as it was affectionately called.
Modules burned so fast every guy had one in his tool box and the special socket to UN bolt it.
Bummer never got to see the after fix of the scope good video
Yes I believe the grease was for under the module. The heat of the motor cooks the module. The grease helps with cooling the electronics.
I hope I never need this information but I'm glad it's available if my '88 stops running. Thanks
The picture that I sent is of a similar module in a 02 5.7 gmc 3500 van. That aluminum heat sink is just for that module. Hope we will get u and Eric to review the Maxi Das. Thanks again!!
+Bill Rimmer Wow so GM finally had the sense to get that module out of the hot distributor for a breath of fresh air and mount it to a proper heatsink?! Cool!
Do you want to see an overview of my older MaxiDas708 or Eric's fancy wireless MaxiSys tablet?
+motoYam. The wireless one Eric has would b neat but if the older one one will do the bidirectional stuff, that's what I am looking for. Some of the comments I have read on Amazon say that the ones they sell r gray market and r difficult to register. Did u buy yours new?
If you own one of these older TBI trucks, you should carry an ICM in the glove box
That is a fact. And the exact right tool to get to it easily.
those modules slowly wear out over time..the heat gets to them. always make sure you apply that heat grease on the underside when you install the new one.my astro van always idled rough and didnt have as much power as tit should..new module solved everything.
Back when I had a vehicle with this ignition I was advised to carry a spare module in the glovebox. They were known to leave dead vehicles on the side of the road.
Excellent video. Big help. Thank you!!
Enjoyed your video. Still have my '88 Chevy Cheyenne with 188K and running smoothly. Could use a new paint job.
Nice diagnositcs. Beats the other method - throw parts at it...
My truck is shutting off while driving! It won't start until I turn the key off then back on. I'll use this video to diagnose - although I don't have scope. Shade tree here....
He’s exactly right about the dielectric grease. It is not to be put on the module itself, just the connectors. Heatsink compound is used on transistors to help with heat dissipation. It’s white and somewhat sticky. Just a little tiny bit will go everywhere it’s not wanted. Lol
I would have also replaced the pickup coil as well. Only problem is the distributor has to be removed and disassembled to access the pickup coil. Takes longer but worth the extra time and money in my opinion.
Petey’s like, ‘seriously dude?’ .
Your suppose to use the dielectric grease on the base of the icm so it doesent get really hot and go bad again
Excellent video, thanks.
A dielectric (or dielectric material) is an electrical insulator that can be polarized by an applied electric field. When a dielectric is placed in an electric field, electric charges do not flow through the material as they do in an electrical conductor but only slightly shift from their average equilibrium positions causing dielectric polarization. Because of dielectric polarization, positive charges are displaced in the direction of the field and negative charges shift in the direction opposite to the field (for example, if the field is moving in the positive x-axis, the negative charges will shift in the negative x-axis). This creates an internal electric field that reduces the overall field within the dielectric itself. If a dielectric is composed of weakly bonded molecules, those molecules not only become polarized, but also reorient so that their symmetry axes align to the field.
Excellent information Sir!
Good to see another way of testing a module GM certified since 87 and don't for sure but thank Manuel will show you how to do it with a test light
Thanks for the comment Scott!
Spark control/ distributor control module had the same issue with my 92 s10 with the tbi 2.8 was scratching my head. My step dad and grand pa both asked if i had replaced the icm and i was like what and thats when they told me yeah inside the distributor cap.
Nice bro thank for the info have a great day
This video looks like great info right away. Hopefully it helps.
Similar thing in my sierra i use to and from for work. Fingers crossed. Cant afford to throw money at it
New engine, started right up. Was running. 1994 chevy c2500 now no spark. New plugs, 2 sets wires, 2 caps, 2 rotor, 2 coils, 2 ditributers, fuses, 2 modules...coil sparks once on key power up make/break. No spark at plugs....
Older HEI distributors, especially those with the coil in cap design, had the module mounted internally beneath the rotor. The dielectric grease was mostly used to to aid heat transfer between the module and the mounting surface. Forget to put some on and the module overheats and fails again in short order.
The thermal grease supplied with the module is supposed to be put on the base of the module to help protect the ignition module from heat
Useful thermal paste to conduct heat away from the module, not dielectric grease.
Good job there I have to buy this diagnostic tool then I have to learn to identify all the engine components and all the accessories in vehicles it will take a while.
+alfred kabura The learning never stops man, definitely takes a while for sure!
That noise was the electric fuel pump, you didn't know that? Also, dielectric grease keeps oxidation down to due to isolating the metal from oxygen, and I think you needed to apply thermal paste to the bottom for proper heat transfer to keep the module from overheating.
that noise was a electric motor under the dash for the air and heat that I know for a fact. Just letting u know. I have an 89 silverado and mine does it. Ive only seen it on the 88 and 89 chevy trucks. my brother has a 90 and it doesnt do it on his
Dielectric grease is not recommended for the bottom of the module. Go to Radio Shack or a computer parts store and get heat sink paiste. It is designed to transfer heat, way better than dielectric grease. I bought a big tube of it off of Amazon. Within a year I've had 2 ignition modules go bad. And I don't buy the cheap ones either.
Thanks for your help.
You should do a introduction video on how you got your start.
thanks Ivan,that video helped a lot.
the included grease goes under the module for heat protection from the engine. Without it module will fail its not for terminals. If you read the directions they most likely stated that as well
That grease is actually supposed to be spread on the base if the icm
Very patient dog in the back seat!!
I know! We miss Petey every day!!
@@PineHollowAutoDiagnostics When did he pass away? He looked like an awesome dog
I agree with everything Bob Weiss wrote in his message 32 minutes ago, which begins:"It is definitely going to get hot".The power transistors usually have about 700 millivolts drop across them, and they are NOT very efficient. It is a PN semiconductor junction.
outstanding video
New subscriber here! Great video! Helped greatly on my 1992 Chevy 1 ton.
Welcome!