Mechanics

WIERD STALLING ISSUE

GMC C2500

I have a 1991 GMC C2500 161k 4x4 with a 454 (7.4) that is Throttle Body Injected. The issue is when the motor has warmed up and I am driving down the road or when I am at a stop light and go to leave it will stall. In order to get it to restart I have to put it in neutral and put my foot into the floor. This does not happen at highway speeds (at least until I go to slow down or stop). In the driveway the fuel injectors seem to be working correctly through the rpms (they pour the fuel in). At idle the left side injector seems to run a bit lean, however, they equal out at around 1000 r's. We have looked at the IAC, TPS with no change. The plugs get carbon fouled in a hurry. The motor had 18 degrees of timing in it which seemed like more then nessecery so I backed it down to 8. The only code that has been thrown was the TPS unit. It has been replaced and the situation still occurs. I thought this might be oil pressure cut off swith however it has occured even with 30lbs of pressure. Tried testing the Torque Convertor (put it in 1st) and the same thing occurs. The diagnostic shop that it went to has said that these sensors can fail within range. It sure seems to be fuel related one way or another. If I start it and let it idle for about 20 - 30 minutes the motor will die. I am really running out of idea's. :
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August 10, 2007.



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