April 29, 2006what would make my truck not idle down when I am in between shifts or when I am down shifting? I have a 1998 k1500 vortec 350 5 speed. When I first start the truck in the morning it will kick down like it should but lately when I am driving the rpm's stay high when I am in between gears .
Forums : Engines-Gasoline : Truck not idling down (355 Views)
April 29, 2006I'd start by checking the TPS (throttle position sensor)
April 29, 2006IAC (idle air control) If the pintle is sticking open then it will cause that.It is located on the drivers side of the throttlebody under and behind the TPS (thottle position sensor).I would start there.They are only about 60 bucks or alittle more.I have seen a few trucks do this and that was the problem.
April 29, 2006Rick hit the nail on the head. I had the EXACT problem with my 1991...it idled at about 1300 rpms. I replaced the throttle position sensor (TPS) and wa-la, no more high idle. Good job Rick!
April 30, 2006My brother and I both have 98 1500 5.7's w/ 5 spds. Both of them idle high between shifts, and don't want to slow down accordingly when you let off the throttle. I replaced the Idle Air Control a few years ago, and it didn't help. I guess it may be the Throttle Position Sensor too?