The truck has 250 000 km on it, it is a 2000 Sierra 4x4 with Z71 package (aluminum block) and lately it has intermittenly been idling high, when in gear with the brake on high idle is approx 750 rpm, and when i shift into park it jumps to approx 1350 rpm, the normal idle for this truck in gear is 500 rpm, and in park 750 rpm, if anyone has any ideas please let me know, thanks
2007-03-31 08:52:07 · 3 answers · asked by Jason M 1 in Cars & Transportation ➔ Car Makes ➔ GMC
Ck around the plastic intake for vacuum leak,they can warp and cause the problem your having.Easy way to ck is to spray carb cleaner around that area and see if engine rpm,s change.
2007-03-31 11:05:57 · answer #1 · answered by deltech 4 · 0⤊ 0⤋
Idle air control valve on the side of the TBI is getting stuck.
That'd be my guess.
2007-03-31 08:58:16 · answer #2 · answered by Mr. KnowItAll 7 · 0⤊ 0⤋
could be a pin hole in the fuel pressure regulator or a vacuum line leak in same general area.
2007-04-01 17:38:46 · answer #3 · answered by (A) 7 · 0⤊ 0⤋