zakbradshaw

I have a 1981 that I let sit for two years without driving due to bad brakes. Finally got around to replacing the master cylinder and driver rear caliper and replaced the battery and it fired right up and drove great. I took it on a few short drives around the block with no issues. Sunday morning I took it out for around 20 minutes and everything was great until I got about 5 minutes from the house. It started bogging down and the idle would drop at stop signs and die. I’d have to put it in neutral and feather the gas pedal to keep it running. Got it home, thought it was a vacuum leak. Changed a couple lines that didn’t look great and fired right back up and ran like normal. Monday took it to work about 10 minutes away. Got into the parking lot and started to do the same thing. Went to leave in the afternoon and drove home perfect with no issues.

Any ideas what it could be? I replaced the intake, carb, and distributor a few years ago to eliminate the computer controlled carb. It has an Edelbrock Performer EPS intake, Edelbrock 650 carb, and HEI distributor.

stingr69

Distributor module needs the special grease under it. Sounds like a distributor overheating issue. Coil could be bad.

zakbradshaw

Okay, I will look into those parts. Is there any particular brand or spec I need to look for? Is one better than another?

HeadsU.P.

Because the IGN system is fairly new, I doubt that's the problem. Usually when a "modge" goes bad it shuts off the fire right now. Electronics are usually On & Off instead of your issue which is, bogging, low idle, feather the throttle, starving for gas.

Yours sounds like a fuel issue. I suspect a fuel starvation problem. Perhaps the fuel sock in the tank is collapsing on itself from all the crap in there. You did let it sit for two years.

zakbradshaw

I need to check the filter as well. The fuel sender was replaced new two years ago.

zigvs

filter

DaveL82

All HEI module failures I have show up after the engine heat gets to the distributor so say 15 minutes. If the car is allowed to cool and then the issue happens again then I suspect the module. My experience is the module failures show up as the car bogging down anytime gas is applied. Mine have never failed fully. The pickup module fails completely.

Fast81

Its either your fuel filter or the sock in the tank. Had this same behavior on another GM car i had. the filter would pass fuel until it clogged from crud then kill the motor. 20-30 mins later after the crud seeped back into the tank, it would fire right up and work for another 20-30 mins until the filter plugged again. Maddening

Dean

Tampa Jerry

One way to determine if it's a fuel related problem is to prime the engine with fuel when it dies.Two years of of the new E fuel can break down and cause havoc for your carb. parts. You can use carb. cleaner and spray it into throat and see if it stats up. You could also use clean fuel in a plastic squirt bottle and prime the carb. Be careful with fuel and a hot engine. If that does not work, try using a can of compressed air on some of your electrical components. The air will cool them down quickly. It's either fuel or ignition. Good luck. Jerry

Gale Banks 80'

If there is a way to add an in line fuel pressure gauge that you can see wile your driving would be the first thing I would do. With out doing that I might try looking down the Carb when its running well and opening the Throttle Blades and watch the gas squirt. Then when its running bad do the same thing and see if the same thing happens. And You could also check the Float Bowl fuel level when its running bad. C3 Corvettes are one of the few cars that You can see the bottom of the gas tank threw the filler cap. I might start there.