Got a frustrating problem, sometimes the car runs great, and then all of a sudden it will flash the check engine light and run bad and go really rich. If it dies sometimes the fuel pump won;t prime, and if it does it will start and immdiately die. I have checked for trouble codes and it has none, so I am thinking it is some kind of a main power wire or ground that would affect the fuel pmp, ignition and the diagnostic port, because sometimes when it goes through the cycle of 12's it flashes like the power is interrupted. The starter always spins over fine, so i am thinking it has to be past that, any ideas before i trade it in for a metro that runs???

 

Quite honestly it could be any number of things. Go over all connections from the battery on up. Check especially the connections at the starter solenoid, it's a major tie point for many voltage feeds. Check the ground strap from the rear of the engine to the firewall, also check the ground from the battery to the block-it may look OK but be electrically poor. I had on and off problems with my 89, redid all the grounds and it seemed to solve many intermittent issues. I also added a couple of supplemental grounds from the engine to the frame. Have not had a peep from the SES light yet.

 

Slow,

Welcome Aboard!

I'm guessing that you scanned for error codes and all you retrieved was the "cycle of 12s". If so, all those 12s you're getting mean that the ECM is not getting distributor reference pulses. That makes sense when you are scanning, since the engine isn't running. However, it could also be a stored code, indicating the ECM lost distributor reference pulses somewhere along the way during and engine run cycle. You might want to check the connections at the HEI module, ESC, and distributor. Once the ECM loses reference pulses, the injector firing stops, as well as ESC timing adjustments.

That may not be your problem, but it would be a good item to eliminate.

 

If the check engine light is coming on and no codes are being recorded it may be a bad PCM. Especially since the fuel pump won't prime too

 

Well, i checked and wiggled every connection i could find on the car, it seems to work now, drove great last night for about an hour, i think when i removed the interior and the fender vent when i got it painted, it disturbed a connection to the ecm. It all seems tight now and we will see if there are any more probs. thanks for the help!!!