possible cause of high idle? [Archive] - GrandAmGT.com Forum


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07-05-2009, 05:28 PM
My IAT sensor pigtail looks like it has been replaced. And not very well at that. The wires are connected to the factory harness with butt connectors. And from what i understand, they work great for a bit, then start to act up and become intermittent problems ( like my problem). Im wondering if it could be working enough to not give a CEL but not working enough to give the correct readings? I think im gonna try redoing that connection the proper way and just replace that sensor, its fairly cheap anyway.

Im just curious if that could be causeing the high idle shortly after startup or not. Ive seen several others post about it, including myself. Im thinking if its sending a reading that its getting air thats -300 degrees or something then it would be acting up causeing the motor to run higher to warm up? WHO KNOWS!! i honestly cant wait to get through boot and sell this car.. been nothing but problems for me. Looks nice though.. lol

07-19-2009, 09:36 AM
well that was not it. I honestly have totally stumped myself, and a few mechanics with 20+ years of experience each. The car NEVER has thrown any error code. at least not since i have owned it. Ive basically soaked this entire engine in starting fluid in search of a vaccume leak. Replaced half of its sensors.

With it being so intermittent, its very difficult to find the cause. One thing i have noticed ( which is what makes be believe sensor of some sort..) is that if i unplug ANY sensor dealing with fuel or intake, i have no problems for anywhere from 2 to 5 days. Then the high idle is back. Basically the only major sensors left are the MAP and the MAF that could cause any of those. Both easy to change. But i can only imagine the cost of the MAF..

Im past whits end with this car. ive gone into plenty of tangents where i just whale on the steering wheel for a few seconds then continue to cuss and scream at this car.. PLEASE help me before i seriously damage this thing..

07-19-2009, 05:14 PM
its the mystery question my friend search this forum for high idle lol

mine does it also very occasionally a high idle and i find if i notice the car is doing it while im driving i slip into neutral and turn the car off then as it slows down to rpms below the high idle point then start the car up again it will go away.

sometimes turning the car of for about 5 min will do it sometimes not.

disconnecting the battery for a min or two works.

07-19-2009, 06:59 PM
yes, i will turn it off and coast a few seconds as well, but its just irritating.. im SUPER anal about my cars and cant stand this kinda thing.

I have searched but yielded zero results that help me.

07-19-2009, 07:50 PM
if you figure it out post it in big bold letters and you will be granted GOD OF THE GA status lol

07-19-2009, 07:55 PM
Soon its gonna have in big bold letters " GRENADE!"

07-27-2009, 03:00 PM
so far its been 100% fine...

It gave me grief for a day or two after, but since then. Nothing. Has anybody else fixed it by doing that?

07-27-2009, 06:43 PM
when i replaced my TPS it was good to me for about two weeks

07-27-2009, 07:43 PM
yea, ive replaced every sensor on the TB. TPS was my first one. It was good for a few months for me.

Saw something on powerblock that got me interested though.. anything on the TB inlet might do it as well.

07-27-2009, 09:01 PM
I also have a bad FPR I need to drop and flush my tank and clean up everything. 10 yrs of 87...:-(

07-27-2009, 09:17 PM
hmmm are you sure that throttle isn't sticking? or getting stuck on something?

07-28-2009, 03:03 PM
yea, ive popped the hood a few times now while thats going on. throttle is closed. and the blades are tight on the throttle " rod " i will call it.