Engine Performance problem
1995 Chevy Silverado V8 Four Wheel Drive Automatic 250000 miles
I have a 1995 Silverado - 2500 (3/4 ton) 4x4 with a 454 (7.4 liter) engine and I just replaced the (automatic) transmission this spring. Since I've gotten the truck back with the new transmission, it has been running terrible - RPMs all over the place, 'coughing', sometimes backfiring... And it dies or stalls almost every time I'm at a stop light or when the wheels stop moving - I need to use two feet (brake & gas) to keep it running at a light.
The 'check engine' light has been on (but it has been since I bough the car [used] a year and a half ago after my previous Silverado was totaled when I was rear-ended by an SUV - but that's another story.)... The codes I've checked since trying to diagnose this running problem indicated the EGR valve and MAP sensor - both of which I've replaced - and neither of which has solved the problem. We also checked the coolant temperature sensor - unplugging/bypassing it seemed to solve the running/idling problem - replaced this [relatively inexpensive part], but again, no fix. I've also replaced the fuel filter and ignition module (more recently it's been giving an 'ignition system' code) - neither of which have solved the problem either.
I've tried all of these:
coolant temperature sensor
none of them have solved my problem.
What can be wrong with my truck? Might I have been the victim of sabotage? (Strangely, not long after the running problem started, each of the four tires needed to be replaced inside of a ten day period - each from seemingly unrelated events - leaks, nail/screw, etc.)
Any insight would be of great value.
have the same problem?
Thursday, August 5th, 2010 AT 4:59 PM