My 91 coupe has all of a sudden started having high idle issues, and I don't know what the dam problem is. I have removed the throttle body, iac, egr, mass air and cleaned them. I have also cleaned the connections on all of them to, including the main connectors behind the intake. I can't find any vacumen issues either, that I am aware of. Also my set screw is all the way out, and the tp sensor has been replaced. Now what? My car starts and idles normal for about a minute, then jumps up to around 1200 rpms and won't come back down. Please help me guys, this shit is annoying.
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annoying high idle issues
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When you did the tps did you reset the idle and check the TPS voltage at idle? Was the IACV really dirty? Have you ever checked the timing?
I had a funky high idle on my coupe this time last year, I had to clean the throttle plate, IACV and reset the idle with the TPS.
320rwhp. 7.67 @ 90mph 1.7 60'
DD: 2004 GMC Sierra VHO 6.0 LQ9 324whp 350wtrq
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The timing has been the same since I got the car, the iac really wasn't dirty, but I cleaned it anyways. The egr was freaking nasty, but it didn't make a difference after cleaning that either. As for the tp sensor, it has been replaced, and at the factory location. I did drill out the holes on one to see if I could get any kind of difference with adjustment, but no luck. I will check for vacuum leaks again tomorrow.
Originally posted by That_Is_My_El_CaminoI grinned, but I have a sneaky suspicion I'm still gay.
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Originally posted by fordplay2 View PostThe timing has been the same since I got the car, the iac really wasn't dirty, but I cleaned it anyways. The egr was freaking nasty, but it didn't make a difference after cleaning that either. As for the tp sensor, it has been replaced, and at the factory location. I did drill out the holes on one to see if I could get any kind of difference with adjustment, but no luck. I will check for vacuum leaks again tomorrow.
320rwhp. 7.67 @ 90mph 1.7 60'
DD: 2004 GMC Sierra VHO 6.0 LQ9 324whp 350wtrq
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Originally posted by 91CoupeMike View PostBeing installed in the factory location is irrelevant, you have to check the voltage to set it correctly. ~1v idle and ~5v WOT. To me it sounds like the TPS and IACV could be the cause. A lot of the time the IACV pin with get carbon build up and cause it not to close properly.
And a lot of times voltages don't mean jack either. This plays a HUGE factor on the GM TPI engines. Couldn't get the idle down on my mom's 89 IROC, finally just let it run while adjusting the TPS, once it settled, it was A OK.
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Originally posted by JC316 View PostAnd a lot of times voltages don't mean jack either. This plays a HUGE factor on the GM TPI engines. Couldn't get the idle down on my mom's 89 IROC, finally just let it run while adjusting the TPS, once it settled, it was A OK.
320rwhp. 7.67 @ 90mph 1.7 60'
DD: 2004 GMC Sierra VHO 6.0 LQ9 324whp 350wtrq
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Yeah.. everything seems to be ok. That's why I'm stumped. Either I'm looking way to freaking hard for something or it right in front of my face. I'm going to look at all the vacuum lines again in the morning.
Originally posted by That_Is_My_El_CaminoI grinned, but I have a sneaky suspicion I'm still gay.
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[QUOTE=91CoupeMike;611633]There Is also a long vacuum Line that goes from the bottom of the upper intake all the way to the EVAP canister under the air filter. Mine was cracked and rotted.[/QUOTE
My emissions stuff isn't there. As for that vacuum line, its blocked off.
Originally posted by That_Is_My_El_CaminoI grinned, but I have a sneaky suspicion I'm still gay.
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