mimaheu

Strange problem just started happening, When I take off from a stand still go then let off the gas the idle will stay up at around 1200-1500 rpm and keep me going at like 25mph as if the cruise control was on or something. When I stop completely the idle will come back down to about 800 or so. The funny thing is that if I take off and the idlegoes high I can put the trans in neutral and idle will stay high then as I come to a complete stop suddely the idle will drop back down again (while in neutral the whole time). I did test and clean up the IAC and it seems to be working as it should according to test procedure. I was suspecting maybe the TPS but not sure how to test that. If anyone has any info on testing the TPS it would be much appreciated, (hate to just be buying parts for no reason). Thanks in advance for any help!

in2pro

I would think that any sensors would set a code, have you checked for any set codes? I would also check the accelerator linkage cable to make sure it doesnt have slack in it or any broken plastic mounts under the hood. Cleaning the TBI return spring might be a good start, also check for any vacuum leaks, cracked hoses or lines and loose fit fittings a vacuum leak will cause a higher idle and won't always set a code.

mimaheu

Ok cool, thanks for all the advice! I had already cleaned up the TBI pretty good with carb cleaner and checked the return spring and all seemed in good shape butI just noticed that a large hose clamp is missing on the hose coming from the air filter box over to the throttle body. It is the clamp right where the hose hooks to the TBI cover. It does seem a little loose so hopefully that's it. I guess the guys that replaced my intake manifold gasket awhile back must have forgot to put that part back on []. As far as checking forset codes, I am not familiar with that , how do I do it? Thanks again for all your help.

in2pro

The air intake to the TBI does need to be somewhat sealed to prevent unfiltered air from entering the engin but it shouldn't cause any major idle changes.
As for an trouble codes, has your check engin light come on or been on in the past? You can have them read/checked/reset at AutoZone, be sure to write them down before clearing them. Or you can buy your own reader http://www.actron.com/,you will find the best prices at www.Amazon.comfor the basic code reader.
I would inspect each and every vacuum hose under the hood especially if you had work done on the engin a hose could be pinched, kinked or disconnected. Also check around the intake a leak there will also cause idle problems make sure nothing got pinched under it. Good luck and let the forum know...

mimaheu

I have never had an engine check light yet. I will go ahead and start checking for vacuum leaks this weekend and let you know what I find, thanks

mimaheu

Update:
I went ahead and bought a hose clamp to replace the missing one on theair intake hose. Took off the IAC again and cleaned it up a bit and cleaned out the hole where it mounts. Also took off the TPS and actually poped it open and cleaned out the inside with contact cleaner. Put everything back together and suddenly seems to working fine again, Idle is down to 600 at a stand still and does not seem to ride high anymore while driving........ Oh well not sure what fixed it we'll see how long it lasts. Thanks again for all your input, much appreciated.