Engine Performance problem
1999 GMC Sierra V8 Four Wheel Drive Automatic 273000 miles
Sorry guys-you have the wife of a very frustrated guy here. I have to ask, as he's at his wit's end, so please bear with me.
Bought the truck 2 weeks ago-(5.9L Sierra 2500), and on the way home up a hill in overdrive it revved out when his foot was on the pedal, but no acceleration, almost like it's in neutral.
When started, it idles low (500rpm) then when put in gear it wants to stall. It accelerates OK otherwise, but is running rich.
Code reader said P0122, so he changed the TPS, & a blown 40amp fuse, cleaned battery terminals, changed plugs and wires, fuel filter, IAC, cleaned the throttle body, MAF, and EGR. He's checked for a vacuum leak, and voltage to TPS.
When he disconnects the TPS and IAC and starts it, it idles just fine for a few minutes, then idles low again.
have the same problem?
Friday, November 21st, 2008 AT 8:10 PM