96' gmc 1500 idles way to high, help??

[jpw2913]

When I crank the pickup it go's up to about 2000 rpm and then drops to normal. However, after driving for only a minute, when I stop and have the clutch in or in nuetral it idles at about 2500-2700 rpm!!
This just started after my battery went dead and I had to jump it off. Since then it has been doing this.
Any advice would be appreciated

Thanks,
Jerry

[SpitAndDirt]

Do you have any check engine lights coming on? My first guess would be that you have a failing throttle position sensor. For it to be idling that high you would have to have some sort of code set. Are you sure nothing is keeping the throttle stuck open, possibly a worn accelerator cable, or binding linkage at the throttle body? Just out of curiousity, are all your battery connections absolutely clean and free of corrosion?

[jpw2913]

I will check the battery cables. Do you think it would help if I disconnected them and reconnected them? Doesn't that "reset" things?
Yes, the check engine light does come on. I don't think it's the accelerator cable. The only reason I say this is because I can lift the accelerator with my hand and it does not slow down. I definately could be wrong.
Thanks a lot for replying,
Jerry

[SpitAndDirt]

Sometimes it will reset, sometimes not. Best bet is to have your truck scanned for free at most auto parts stores and write the codes down. Check www.troublecodes.net for more info.

[Kevcules]

The first thing that comes to mind for high idle is your throttle body gasket is bad. This happened to my 91 half ton and I replaced it and problem gone. Since you have a trouble light on , you should get the code. My truck manual tells me that I can jumper two terminals at the code reader connection, with a wire, and read my own codes on my truck. I have done this many times, it's easy. I'm wondering if you could do the same , check with someone or your manual, for your year truck.
I also diagnosed my throttle position sensor was bad one time, after getting a check engine light. It didn't idle any different but performance was lacking. This is because the computer goes into a default mode to make sure the engine will continue to run when it encounters failure of a component. The tps is very easy to replace but check and see what code error you have first.

PS... disconnect the neg battery cable for ten seconds to reset codes especially after a component has been replaced. If the problem is intermittent, the trouble light might go out for now.

Good Luck

Kevin