Engine Performance problem
1998 GMC C2500 V8 Four Wheel Drive Automatic 194000 miles
Replaced plugs when noticing a drop in voltage from the alternator, plugs were way overdue. Truck ran great for a week then started running rough and getting progressively worse. Fuel pump failed, replaced pump and filter, did not correct engine running rough problem. Have since replaced cap, rotor, wires, tested fuel pressure good at 55psi. Everyday the truck runs worse then before, everytime I stop at a light it wants to stall it's running so rough, if I place the truck in neutral or park, it smooths out a little but still runs rough. I've tried injector cleaner and high octane fuel, no change. All of the above transpired over 3 weeks. Pulled all the plugs again, all appear to be firing though the trucksounds like it's misfiring. Any ideas? Running out of ideas here. Thanks
have the same problem?
Tuesday, April 13th, 2010 AT 8:42 AM