High idle sometime

[duber3]

HI!
Last year I had a high idle on my 1986 GN but only sometime!
this year I changed the IAC (brand new ac delco), with my scanmaster, I adjusted the IAC at 18, TPS at .42 engine Off and the idle was at 825rpm, perfect, took the car for a little ride, returned home, damn!! idle at 1100rpm, IAC at 43?? stop the car, restart it, idle 825rpm, IAC 18, I removed the IAC, cleaned every holes reinstall it, still the same thing, after 30minutes of run the idle is sometime at 825rpm, IAC 18 and sometime idle at 1100rpm, IAC 43

I have TT chip 16-18lbs boost with 42 lbs injector, te44 turbo, hot wire, walbro fuel pump
changed every vacuum hoses,

thank!!

 

[TurboBuRick]

Last time I had a problem like that it ended up being something with the chip. Do you have another one you could try?

RL

 

[duber3]

Last time I had a problem like that it ended up being something with the chip. Do you have another one you could try?

RL

I only have the original one, I know that when the car was 100% stock, I didn't have this problem, maybe you'r right!!

 

[TurboBuRick]

Get with Eric. I'm sure he would send you another chip to try. He might have another idea as well.

His screen name here is Eric Stage I or jump on his forum.

RL

 

[duber3]

Get with Eric. I'm sure he would send you another chip to try. He might have another idea as well.

His screen name here is Eric Stage I or jump on his forum.

RL

Thanks for your help!!

 

[duber3]

OK I think that i found the problem
with key on, engine off with the car in drive, when I put it in neutral and try to start the car, I can't turn the key
it's like the Park/Neutral switch is not completly in neutal position, if I return the trans in reverse then in neutral, now I can turn the key and start the car

I've read that this ajustement need to be done at the rod, can someone give me a clue how to adjust it, it will be very appreciate

thanks!!

 

[GNONYX]

It seems you have two problems which I think are not related with each other. One of your problem since you replaced the IAC you will need to reset it, and one of our member had this, so try it and see if it will work for the idle problem.

​

MANUALLY “RESET” THE IAC BY PERFORMING THE FOLLOWING​

Jumper ALDL connector pins A and B. (top right two pins) ​

Turn the ignition on but do not start the engine. The ECM sets the IAC count to zero.
Wait 30 seconds so the IAC has more than enough time to seat the pin. Leave ignition on.With ignition still on, disconnect the IAC electrical connector.
Turn the ignition off, remove the ALDL jumper, and reconnect the IAC electrical connector.This establishes the seated or zero reference point.
The next time the engine is started, the IAC will go to a count of 150, then count down (extend) as the engine warms.
I have this on how to adjust the steering column rod, let us know all works well.

 

[duber3]

OK I did exactly what you gave me for the IAC
I've let the car warmed up, restet the IAC per your method, adjusted the TPS
in the garage, the car was really warmed up, in park, IAC 18, tps: .44 idle 825
put in reverse, park, drive neutral etc. etc. everytime, the idle was perfect, in neutral or park, the IAC was at 18, idle 825

but...when I took the car for a drive, at a red light, put the car in neutral, the IAC stayed at 46
there is no vacuum leaks and no exaust leaks, it append always during a drive

as for adjusting the control shift rod, I will do it this winting, anyway i'm about to store the car for the winter

 

[imjoesnuffy]

What is your TPS at when it starts to idle high? TB returning to the fully seated position after driving?

BLMs at high idle?

 

[duber3]

tps is at .44, the INT is at 128 and the BLM 124, like I said in my first post, when it append, if I turn off and restart the engine, everything went perfect

 

[duber3]

Well... After 2 years, I finally solved by accident this annoying problem,
This year, when I took the car for the first time, I had 2 check engine with code 22, Tps low voltage
I had this code last year but I thought that the connector pins was loose, I tightened the pins and the code disappeared, but this year, 2 time in 30minutes, I decided to buy a new TPS, and voilà... no more high idle
Like I said in my previous post, all the readings was perfect when the High Idle appeared so I never thought that the TPS was the culprit, I hope this will help other !!

Thanks!

 

[psycho6cyl]

Great thanks for update..

 

[GNONYX]

I'm glad you found the little bastard, now enjoy your ride

 

[larry33kc]

Good job. Is there a way of testing it so you would know if it needs replaced.

 

[duber3]

Good job. Is there a way of testing it so you would know if it needs replaced.

I don't know, maybe someone here can answer this question, the only thing I can add is that the trouble only appeared when the engine was hot
and the temp under the hood was high too.

 

[earlbrown]

The scantool should have been reporting the out-of-spec TPS reading while the idle problem was happening. but thinking to look there at just the right moment to catch it is another story.

 

[GNONYX]

The scantool should have been reporting the out-of-spec TPS reading while the idle problem was happening. but thinking to look there at just the right moment to catch it is another story.

I guess this is where more than one bottle of beer is require to obtain more than two eyes.

 

[earlbrown]

Yep!


or a powerlogger file when it's acting up.

 

[duber3]

I'm glad you found the little bastard, now enjoy your rideView attachment 226747

I always enjoyed my car even with this annoying problem I had , every time I go for a drive,
I don't know how to explain this but it like that the time stop, I really enjoy me car