Hi all,

Newbie here with some questions regarding an all original '82 vette with less than 17,000 miles on it. It has an intermittant but fairly regular stalling issue when warmed up; usually stalls out at slow speeds or at idle but hasn't yet at higher speeds (freeways). Got a new ICM, '85 fuel pump, plug wires, new cat, new o2 sensor, and a rebuilt 700r4 but still winding up in no-start conditions. Pretty sure the engine is flooding cause it'll usually start up relatively easy with the throttle open.

I suspect the ECM is failing or the MAF relays are going bad but was hoping the folks here might be able to throw out some other suggestions. Read through the sticky and done most of the suggested troubleshooting, but the stalling persists.

Reasons I suspect the ECM or MAF:
1. New engine coolant sensor but throws code 15 every once in a while; feels like the engine stumbling when it does but doesn't stall
2. ECM throws code 33 (MAF voltage high) when it stalls out; throws code 34 (MAF voltage low) if I unplug it
3. Car runs beautifully when cold; even runs amazingly until I suddenly notice that I've lost power
4. Occasionally feels like the torque converter is slipping after the car warms up usually at higher gears or OD.
5. Checked all the grounds and the vacuum lines I could reach and they look solid; the car was garaged for 30 years under a cover so most of the stuff looks and feels brand new.

Thanks!

 

First off...do you have access to a scanner????

Do you have the factory Corvette service manual??? I mean the REAL ONE...no Chiltons, Haynes or Mitchell books.

There is a lot going on here that trying to do it without some specific equipment ...makes it really hard.....and getting the needed jumper harnesses and a volt/ohmmeter is needed if you are going to try to diagnose the problems without the benefit of a scanner.

Knowing all of what you have tested and verified would be GREAT...so comments are not that of something you had already performed.

DUB

 

http://www.ehow.com/list_5946595_sig...ckup-coil.html I was thinking pickup coil because you said it happens when the motor gets warmed up.also with that low of miles the car a has sat a lot I would check and clean all connections on the computer.

 

If you don't have a GM Shop Manual, get one. Also, you do not have a MAF sensor on a CFI motor, but you do have a MAP sensor. Maybe it was a typo.

Code 33 is MAP voltage high. Most likely cause is open circuit MAP to ECM, bad MAP sensor or ECM. You said you replaced the ECM, why was that, just wondering. Since you said it works OK while cold or Open loop it could be either one of the issues I mentioned since the ECM uses set variables at cold start.

Code 34 is just about the same, but MAP voltage low, but checking a few more things. The ground CKT is 455, not 469 that you need to check. Also, is the hose on MAP sensor OK and not cracked/split? I'm only guessing at this point, but sounds plausible. Post back results. Good luck.

 

I chased the same problem on my 84 which has the same motor. Finally replaced the computer and runs like brand new. I'd replace the computer.

 

buccaneer.do you have a cable from the obd 1 to the usb?or do you use a scanner.

 

I don't... PM sent.