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High Idle stuck

E

eddie07

New member
Needing your experience and help with my car.its a 2002 Pontiac gran prix gtp 3.8L SC
Gtp idles high at idle and gear. 1.8-2.3k Rpm at idle 1.2k Rpm in gear
Changed
3x throttle bodie
3x maf
3x iacv
3x tps
No combination seems to work
Found a few bad wires and have fixed
Break clean (flammable spray smooth out idle) vac leak and cannot find one that takes the idle down only if sprayed directly into intake does make the idle go down. Even tried a different pcm Stock tune and still idles high with that pcm I'm at a lost I did the LIM a few days ago and still have that high idle ....
 


I'd smoke test it to make sure there is no large leak.

Have you tried starting it with the throttle cable un-hooked. Maybe the cable is holding the blade slightly open?
 
both CControl and main cable are off and the TB butterfly valve is shut all the way you can see it thru the honeycomb screen and I'm pretty sure there no leak I used carb cleaner sprayed the obvious spots and no idle change like said I even did LIM and still same problem LTFT +16
 


Fivefingerdeathpunch said:
Then something must be letting in the extra air.

Carb cleaner or brake cleaner doesn't always work, why I suggested a smoke test.
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thanks for the idea but its just so weird how this occurred man I went to lunch got food tunred my ac on and got back parked and it idled high had to get towed from work because it didn't go away
 
eddie07 said:
both CControl and main cable are off and the TB butterfly valve is shut all the way you can see it thru the honeycomb screen and I'm pretty sure there no leak I used carb cleaner sprayed the obvious spots and no idle change like said I even did LIM and still same problem LTFT +16
Click to expand...

Clogged Cat? Something is causing the Oxy sensors to tell it to add fuel... Right?
 
Trim pegged at +16 is a vac leak... Unmetered air is getting in... You have to find it. Deleting the EGR because of a code doesn't fix the leak. And what was the EGR code deleted? Don't you think the two can be related?

Can't hide from a smoke test, is best way to find leaks. Don't mess around, get a smoker, make one, or take it to someone who has one and give it a shot.
 
eddie07 said:
thanks for the idea but its just so weird how this occurred man I went to lunch got food tunred my ac on and got back parked and it idled high had to get towed from work because it didn't go away
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Have you checked the vac line that enters into the car for the HVAC system for a leak, has to be a vac leak somewhere with the +16 LTFT
 


its the back o2 that reads +16 ltft ill look up the code foe the egr ina few and I feel like I'm almost positive theres no leak it ran fine I even added a SSIC before it did this thanks coolone
 
yes all my lines are connected i read on another forum that this guy had a simalir issue and he got another pcm tuned and went with stock tune added a few things and drove it at 1.1k rpms and eventually it went away but idk about driving at that high rpm and especially in this las vegas 107+ weather
 
eddie07 said:
its the back o2 that reads +16 ltft ill look up the code foe the egr ina few and I feel like I'm almost positive theres no leak it ran fine I even added a SSIC before it did this thanks coolone
Click to expand...
Nope...the rear 02 sensor does not read fuel trims. You did mention above that the rear o2 was tuned out anyhow.
 
also forgot to mention I was getting the intermediate tps could and low 5v reference signal but even with new wires from pcm to tps it still threw it and I forgot was the stft and the front o2 would bounce between 100to 900v
 


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