I purchased a 1982 corvette in August 2023. Since then I’ve put about 1000 miles on it. In the last 100 miles or so it’s developed a problem where it will die randomly. When it does die, there is no sputtering, the engine just stops. There is still power for the lights and radio. The CEL comes on but does not come on when I restart. I have not yet attempted to restart without completely turning off the car off. I am able to get it to restart in under a minute if it does happen.

I am able to coast if I need to.

I am going to be replacing the fuel pump due to an issue with the fuel sending unit and also upgrading the pump to an ‘85 fuel pump.

however, I feel as though the issue I’m experiencing is unrelated. From another forum post I’ve seen where it could be the Ignition Control Module or the pick up coil.

Before I go and just throwing things at it and hoping to resolve it, I am wonder if there is anything else I should look at? Any symptoms I can try to identify that will help isolate what to replace.

The last time this issue happened was just today. I was driving about 70mph on the highway when it died. Coasted to a stop so I didn’t cause a crash behind me and turned the car off completely and after two attempts it restarted.

 

Your first clue was/is the CEL. When it dies, get the code set, that is your starting point. BTW, if you don't have a 82 GM service manual, get one. Your going to need it.

 

I failed to mention it in my post. I have already attempted checking the CEL and only getting 12 as the code so no other codes appearing. I have not checked it with this time though but from the last time I checked there was no code and I have not unplugged the battery or anything like that.

 

This is why when those cars were new they were labeled Cease Fire.good luck.

 

Code 12 = LS swap

 

Oh, stop! Nothing wrong with CFI. Just need to un-bubbafy it to get it to run properly. Once that is done, they are like the Energizer bunny, they keep running and running... No need to slam an expensive LS motor install in it for a simple issue, be serious.

 

Damn, that would really get the heart going!

I have just about zero experience with the cross-fire or even HEI ignitions, but... this sounds electrical in nature. The ignition control module is where I'd lean - when they begin deteriorating, it seems they shut down randomly. Heat can also affect deteriorated electronic components to fail, so driving at 70 is going to generate some heat.

 

I had the same problem on my 82. I'd be driving down the the rod and it would dive for no apparent reason. I would shift into neutral, turn the the key off and back on and then restart it. This went on for nearly a year. Sometimes it would go a couple of weeks, sometimes multiple failures on same drive.
I tried alot of things to fix it. Most were related to various parts of the distributor. I finally replaced the entire distributor with one from carparts.com for $91 with tax & shipping. I hace since driven the car over 4,500 miles and no failures.

The other post that you mention may hve been the one I started. Many thanks to the forum members for helping me solve my problem. It was multiple components within the distributor that wren't completly resolved until complete replacement.

I hope you resolve yours soon, the car just randomly shuttoff is a bit dangerous.

 

Check the wiring to the oil pressure sender (it controls the fuel pump also)

 

Not while running. You can unplug the sender unit while running and it will remain running. It's a fail-safe/backup for the oil system.

 

May start a new thread on this as a new issue started up.

I pulled the distributor and installed a new pick up coil/magnet along with a new ICM. I reinstalled the distributor and rotor to exactly how it was before I took it out. Cap and rotor look good.

Now I have a very rough idle situation before the engine eventually stalls. For example RPMs will drop down to 400 then go back up to 800-900. No consistent idle at all and then stalls.

my initial thought is that it needs to have timing reset. I do not have a timing light yet and plan to get one in the next day or two. I have attempted to turn the distributor ever so slighting in one direction or the other but I do not get any smooth idling. I’ve double, triple, and quadruple checked all the connections are correct, verified the spark wires are set for the correct cylinders, no loose connections, all vacuum lines are good.

Any ideas? Is it just a case of bad timing?

 

**UPDATE**

So I decided to revert all the distributor components back to original, reinstalled pick up coil/magnet and ICM. Made sure the distributor was aligned to TDC. Turned the key and it fired right up and back to the RPMs I was used to prior to swapping the parts.

Leaning towards going the route nascar9and19 and replacing the distributor. However, I would rather go cheaper and try to just replace the pickup coil. I originally purchased a Standard Ignition one from O'Reilly to which I will promptly return.

The distributor that I currently have is a Delco Remy to which I found an ACDelco coil on Amazon. I'm thinking that maybe since it's AC Delco it would be like for like replacement.

Before I make any rash decisions with my wallet, could anyone spare a thought?

 

If you are going to replace the distributor which may be causing your issue for sure. Go with a good one. Here is a good choice and it isn't too expensive. GL DUI Dizzy
You want the one on the left "L clamp" Shop around to see if you can find it a little cheaper. I run this same distributor in my 82, works great.

 

Thank you for the recommendation! I will keep that in mind if/when I go distributor shopping in the future.

** Minor Update **
I received the AC Delco pick up coil today and promptly installed it. I fired up the engine and ran it for about 10 minutes and applied around 2K RPM for a minute or so with no issues. I've reinstalled the distributor as it came out initially but feel as though I need to time it which I will look to do either today or tomorrow. Hopefully I can get it on the road soon and properly test it out and see if it dies out again.

 

While I wait for the timing light to come in (should be tomorrow), I ran the engine to get up to operating temperature. I sat in my driveway while I let the engine run, idles just fine. I did not apply any additional RPMs other than idle. It seems like once it got to operating temperature is when it shut down. I was then able to fire it back up and had no problems for the next 15 minutes or so.

I found the paperwork that I received with it to see what work had been done prior to me purchasing it. According to the document the work was completed in July of 2022.

Relevant repairs performed prior to purchase:

• Ignition Module - LX315 - Standard Motor
• Distributor Cap - D336X - ACDelco
• Distributor Rotor - D448 - ACDelco
• Spark Plugs
• Spark Plug Wires
• Fuel Filter

What I have replaced since:

• Ignition Control Module
• Pick Up Coil - AC Delco
• Fuel Pump - Upgraded to 85 pump
• Fuel sending unit

Left to potentially replace:

• Oil pressure switch
• Fuel Pump Relay
• Ignition Coil
• Distributor Wire Harness with Capacitor
  Distributor Wire Harness with Capacitor
  (I have already ordered and waiting on the Distributor Wire Harness to arrive. As soon as it does I will be installing it. )

Distributor cap/rotor appear to be good, no cracks or signs of wear.

I inspected the ignition coil and it appears to be fairly new. Wires were still copper in color, no patina. Plastic seemed brand new with no signs of aging or cracking. I didn't see it on the repair sheet but doesn't mean it wasn't taken care of at some point. Only thing I can't tell is if it was an ACDelco part or some other brand. I'm guessing its likely not ACDelco but unsure.

I could see it being a combination of the oil pressure switch and the fuel pump relay. However, I would think that if it was the relay or the oil pressure switch that I would have more issues with it than I currently do. I figure once oil pressure switch takes over from the relay that if there was no pressure then it would have died. I also figure that if it was the relay that I wouldn't be able to hear the fuel pump prime when I turn the key to the on position (before starting the engine). Could it be because once the engine gets to operating temp the ECM goes into closed loop and then triggers the fuel pump relay and if the relay is bad, its not properly making the switch and therefore cutting out? I'm spit balling at this point.

Also looking to potentially swap out ICM with ACDelco.

What else could I be missing?

 

Just curious at this point, but do you EVER get a CEL? If so, what is the code? No codes set mean that the ECM doesn't care what is going on or isn't monitoring the issue. However, if the ECM is bad, it may not care what's happening. I find it odd, that the engine dies and then restarts with no issues. I have seen issues similar to this, but usually sets a code 42/43. I would not worry about the relay or the pressure sensor. Also, you did apply heat transfer grease to the HEI module, right? If not, it will heat up and shut the engine off. I use Arctic Silver5 paste on all my modules and works great. Are you saying you think the issue may be the ECM? If so, you will NEVER find one and if you do, it is 42 years old and why would you buy that? If you plan on changing the ECM, contact me, I can help and give you a much better option.

 

Only time I get CEL currently is when it dies just like when it comes on before starting the engine. However once the car is running no CEL comes on.

I do not believe the issue to be ECM related. At this point I believe it’s either the fuel pump relay, oil pressure sensor, ICM, and/or Ignition Coil.

Oil pressure sensor seems to be fine as the needle doesn’t shake. It gets to pressure and may adjust based on condition but doesn’t bounce around at idle.

edit: I did apply the heat transfer grease before installing the ICM.

 

** Update **

Received the new ACDelco Wireharness and ACDelco Ignition Coil. I got those installed and fired up the car. All seemed to be well and was running for about 10 minutes or so before promptly stalling. Same as before, no hesitation or anything like that, it just dies. I restart it and it goes for maybe 3-4 minutes before stalling again. I fire it up one more time and it goes for about 10 minutes before stalling again. Same as before, no symptoms, just stalls.

While it's stalled, I leave the key in the on position and attempt to restart it without turning the car off all the way. It does not start up. Looking in the throttle bodies (air cleaner removed). I could not see any fuel coming from the injectors. If I turn off all the way and then turn on, it starts up right away.

I remembered that the air cleaner valve has the same relay as the fuel pump. I decided to swap them out, I figured worse case scenario the air cleaner's relay is not working and I will just reinstall the one from the fuel pump relay. I was able to get the car started up with no issues. It ran for maybe 6 minutes.

At this point at the distributor I have a new pick-up coil, wire harness, and ignition coil. Cap and Rotor look in good condition. I reinstalled the ICM that came with the car (going to try swapping it out with the other one that I purchased). Replaced the fuel pump / sending unit and fuel pump relay.

I am thinking I might swap out the fuel filter next. Even though it was supposedly swapped out (I have not yet got under the car to verify that the fuel filter looks new), I did notice that the fuel pump sock on the old one was super beat up when I took it out.

On that note, I have been tinkering with the fact that it could be the fuel filter getting clogged up which could potentially explain why it dies so frequently. However, I would think that if it was the fuel filter that it would hesitate due to declining fuel pressure or just not start at all.

Related to timing - While it was running and once I was able to get it up to temperature, I was able to set timing to 6 degrees before TDC. I followed the correct procedure by unplugging the EST wire while engine was off and reconnecting afterwards. I also unplugged the battery for roughly 45 minutes before starting back up again.

Any other thoughts or things to look into would be appreciated.

 

Will it die if you keep it on a constant fast idle?
Does the exhaust feel strong and equal between the two tail pipes?
(I don't think it's a fuel filter because once it's clogged, it's clogged and it wouldn't have the short run-times before restriction.)

 

first check all grounds, then you find out whether its gas or electric problem so i would leave air clear off and when it dies don't touch key put some gas in both cfis and try to start it. if starts its gas problem.if it don't put voltmeter on 12 wire that powers dizzy see if power disappears. while it dies. Could be bad starter solenoid getting hot.