hey nice site guys,

Ive got a 95 1500 5 speed that has been maticulously maintained sense new but the 4.3 vortec has developed a slight problem. upon cranking the vehicle and sitting at red lights the motor revs up to 2600 rpms. It does not just happen when the engine is cold, but does seem to happen only for a short while after start up. For example: Cranked it up this morning cold and it revved to 2600 even while in gear. ran it down the road for 20 minutes and noticed it was not doing it anymore. parked the truck for 5 minutes and cranked it again while hot and it started doing the same thing. It seems that once the engine has been put under a load (3rd, 4th and 5th gear) it quits doing it.

any thoughts would be greatly appreciated.

 

clean the egr and idle air control valves. also check all vacuum lines for leaks.