Hey whats up guys! So I am new to this whole forumn thing but I am loosing my mind trying to figure out what is wrong with my 81. So I just recently bought an 81 Corvette (Automatic) from a co-worker. When I first test drove it sounded good and the body lines just sold me. We ended up agreeing on a fair price and I drove the car home with no issues. A week later I am driving it around town and it dies on my on a Red Light. It turned over but wont start. I ended up getting the car towed home. I had a family mechanic come look at it and he said that it had to be the fuel pump so that got replaced; also replaced a rusted out battery terminal, tested the battery and alternator. All were good from what it seems. The car then still continues to turn over but wont start. Out of the blue one day though, it just starts. I was relieved thinking the issue was solved. So, I then leave the car on in the garage prior to going to work and then it just shuts off and once again I cant get it going again. Once again I get it towed to the mechanic and he checks the fuel line and starts checking the carburetor. The car the next day once again starts out of nowhere but as I'm driving to car the car dies at a stop sign and it turns over but wont start. This time we take the carburetor out and have it tested. Mechanics who look at it say its not the carburetor..so at this point I am back to square 1. I am not the most mechanically inclined individual out there so maybe getting such a complicated beast was a mistake but I really like the car and the price I got it for just seemed like it was worth the risk. Any help with be much appreciated guys. Thanks!

 

welcome to the wonderful world of the C-3, sorry your having problems but we'll get you fixed up in the end and you'll love the car.

my first recomendation is to complete your profile so we know where you are, there may be someone in your area that can help you out with this or other problems.

remember, you're dealing with a 30+ year old car and things do go wrong.

all that said, there are only a few things the engine needs to run---fuel, compression and spark.

it sounds like you have had the fuel partially addressed by doing the fuel pump, but the carb on your car is computer controlled (if original), and that adds a little more to the equation.

you can pretty much rule out compression issues because the car does run when it wants to, and compression is either there or not, it doesn't come and go. that leaves fuel and spark, my bet is on spark,

having an intermittent problem is hard to figure out but it's doable, we dont' want to just throw parts at it so it may take a while to figure out. first, I would wait till it won't fire up and then start checking things. pull a spark plug wire and spark plug (which ever is easier to get to), put the wire back on the plug and lay the plug with the threads against something metal (grounded), then crank the engine and see if you are getting spark from the plug. if so, we need to start looking at the fuel system. if not, there are a few things to look at for the spark issue.

you will need to do this before we can proceede with fixing it. let us know what you find and we'll go from there.

 

There is an "ignition module" doohickey under the rotor on the drivers side of the distributor. It's half moon shaped with wires connecting on both ends, that is held in place by two screws. Mine would go out when the car warmed up. It would restart when it cooled down. I replaced it twice and finally purchased a AC Delco branded one and all has been fine.
Might be something to look into.

 

+1. I'd replace this module for sure before doing anything else. This is something you can do yourself and as suggested, go with a Delco part.
Pick up a GM shop manual for the car also which will pay for itself many times over.

 

I agree that the ignition control module, is a good place to start. The AC Delco module, is part number 19179581.

If the control module doesn't solve the problem, I would probably try a coil next. The correct Delco coil for your 81, is D504A.

Welcome to the Forum, and the 81 owner's club!

 

As a fellow 81 owner who has had to chase gremlins from a previous owners crazy mistakes, I have become very aware of the 81 and it's CCC function. I will be happy to help as well. You will find you get great advice on here and you already are ... A few q's..,
1. Is the original E4ME carb on the car? * will have two computer connections to the carb
2. Is the check engine light on ? * search the forum for my thread "81 q-jet time for Lars?"...I posted a video if how to scan codes on the 81
3. Is the original electric controlled distributor installed ? * if it's a vaccum advance it's not tr original

Brian

 

Thank You fellas for all the freat info. I will start with that Module & go from there.
-Brian, i will check once I go see the car today & get back to you. Preciate the reply

 

I think you need to verify what is killing the engine! When it dies, you have to pop the hood and check for spark and fuel. 2 very simple tests and which ever one fails you can correct pretty easy. You're assuming that the fuel pump is replaced and your fuel problems are solved. That may not be so. It can be debris in the tank or a fuel filter still causing problems.
If you have no spark, then yes, I would look at the module or a loose wire.

 

post a picture of your engine compartment

 

So, the car is still equiped with the Stock Carburetor (q-jet) and distributor from what it seems. The engine light comes on momentarily when turning the car over but then it goes away once on. Also, called the previous owner & he said he had everything stock besides regular maintenance replacements. The fuel filter itself was clean when I took it out the first time when tbe fuel pump was replaced. Is there any ither pump these beadt come with I should look for??
Il take a pic of the engine once I get the car back, for sure.

 

What does the car idle at in drive and in park? this could just be an issue where the idle is too low in drive and you flood it out trying to restart it.

when ignition modules fail, they usually completely fail and aren't intermittent.

like said above you need to do some test while the no start condition is happening first.

 

There is only 1 fuel pump, same on GM cars for 30 or more years before this one.
If you have fuel to the carb it has to be ignition.
If it dies again, your going to have to verify fuel getting to the carb by removing the air cleaner lid and checking to see if it getting fuel by pumping the accelerator while looking down the throat of the carb. Without the requisite troubleshooting skills going further will be tough, but we can teach you, no problem. The value in the fuel exercise is eliminating fuel from the problem. After that your going to have to pop for some parts, Ignition module is a good place to start. I have not had a carb produce an intermittent problem like you describe, electrics all the time.