high idle (scanmaster numbers inside)

[booth1]

like the title says im having a high idle issue and i would like some of the guys to go over my numbers and hopefully lead me to a fix. so here goes. this is after about 10 min of driving on this chilly 70 degree morning in louisiana

808 0.0
af 07
l8 36
bat 13.2
int 128
mph 00
clt 165
ats 126
r 1100
tps .42
iac 00
cc 89
mal 00

 

[TRYMYSIX]

IAC is at 00....Set it from 10-30 and should be fine

 

[booth1]

wouldnt that make it idle higher?

 

[turbo nasty]

The guy is giving you good advice. Your IAC does not fall with in spec 10-50 is normal range. Sounds like you need to do somemore research...TPS, IAC is the basics for learning these cars.

 

[TRYMYSIX]

wouldnt that make it idle higher?

You can't adjust one without the other (i.e. IAC and TPS). Adjust IAC between 10-30 or 50 as Jason suggest, the idle will climb, then adjust TPS to .42-.46. If IAC won't adjust, you need to clean it, replace it, or reset it. Try this IAC Reset Procedure

 

[TurboBuRick]

Check for vacuum leaks first then reset IAC as recommended.

 

[theCATman]

Check for vacuum leaks first then reset IAC as recommended.

This...X2

if no workie.....

Then maybe this....http://www.turbobuick.com/forums/general-turbo-buick-tech/359146-trying-get-iac-set-right.html

 

[booth1]

ok so i have located the adjusting screws for the tps and i have located the aldl and iac connector. will i need to find anything else before attempting to adjust this? are there actual iac adjustment screws? and what would makw this so out of whack all of a sudden? does anyone have a part number for a new iac just in case i find mine is n.f.g?

 

[booth1]

ok so i tried to reset rhe iac but this is what happened. first i couldnt get the rpms down to 500 i got 650-700 when the idle stop screw backed all the way out. then i set the tps to .42-4.8. but the iac was still at 175. any input will be greatly appreciated

 

[WH1_T-Type]

I'm working through the same issue right now (weather permitting).

Advice I have received so far:

Pull the uppipe and see if there is any gunk built up around the throttle blade, if so, clean it.
Pull the IAC motor and clean the connections, reseat it fully.
If that doesn't work, replace IAC
-OR-
begin hunt for a vacuum leak.

Other option is do the hunt first and then replace the IAC motor.

If it is a vacuum leak, there is unmetered air getting into your engine and the ECM is trying to compensate for that by dumping in more fuel and basically bypassing your IAC completely.

 

[Steve V]

do not forget the throttlebody seals.
besure to read and understand gntypes procedure.
this is basic stuff,I have not seen Iacs go bad often
If the blade is open at idle iac has no control of idle.
I should be mostly closed so the iac can pull back its pintil and let air in to raise the idle. If the passage is carboned this won't work well. If the tbody blade is being held open by carbon it won't work well either.
post back if you have anymore questions I won't be far from the net as
i am confined to the house with my newborn!:biggrin:

I'm working through the same issue right now (weather permitting).

Advice I have received so far:

Pull the uppipe and see if there is any gunk built up around the throttle blade, if so, clean it.
Pull the IAC motor and clean the connections, reseat it fully.
If that doesn't work, replace IAC
-OR-
begin hunt for a vacuum leak.

Other option is do the hunt first and then replace the IAC motor.

If it is a vacuum leak, there is unmetered air getting into your engine and the ECM is trying to compensate for that by dumping in more fuel and basically bypassing your IAC completely.

 

[WH1_T-Type]

I was gonna ask in my thread, but this is a good place to so the OP can learn as well,

What is the best way to check the TB seals? Same as what the other ppl were recommending for vacuum leak checks? Or more of a visual check? I think I will probably just do the R/R and clean it up like you suggested if the weather permits this coming Monday.

 

[Steve V]

I was gonna ask in my thread, but this is a good place to so the OP can learn as well,

What is the best way to check the TB seals? Same as what the other ppl were recommending for vacuum leak checks? Or more of a visual check? I think I will probably just do the R/R and clean it up like you suggested if the weather permits this coming Monday.

look for build up around the linkage and Tps on right side. Spray a large volumn of carb/brake cleaner around those areas.

 

[booth1]

say i wanted to pull my tb off to clean it where would i get a gasket for a kenne bell 70mm?

 

[Steve V]

say i wanted to pull my tb off to clean it where would i get a gasket for a kenne bell 70mm?

Go to parts store and get gasket paper and cut one out from the original. Easy and cheap. And Kirban/gbody do sell them if you want them already cut.

 

[booth1]

no need i removed the up pipe and shes clean. so i removed the iac and turned the key to on. the iac read 146 no movement so i turned the key to off jumped out the aldl turned the key to on and iac read 00 but still no movement. i think im going to pick up a cheapie to swapp it out and see if it changes anything. if so ill order an acdelco

 

[groumoutis]

First of all that is not the idle screw. It is the idle air control screw. It doesn't really control the idle the ECM does. You are going to have to dance the dance. You need to adjust the screw to get the iac to be between 10 and 50. Once you do that you will find that the tps is now off. Adjust the tps and then back to the iac. See why I called it a dance? You will probably have to do this a few times to get it right. If you don't have someone in the car with the common sense to do the go fast pedal and read the SM tps numbers for you then it will get really frustrating.

Just take your time and go back and forth from the tps to the iac until you get it zero'd in. Once you get it you shouldn't have any problems with it. My car idles between 800-900 but is usually 850-875. One thing I have learned is when someone gives you advise on this board is that you trust them and do it and then ask why it worked after you fix it. I had the same problem with the my car as you are having now and I got the same advise I just gave you. Just mess with it and you will eventually get it set.

 

[WH1_T-Type]

Been covered..we are kinda past that point and already established that there is more at work then the adjustment being off. Which is why he was talking about jumping the ALDL and removing the uppipe...

 

[booth1]

First of all that is not the idle screw. It is the idle air control screw. .

is there more than one?

 

[WH1_T-Type]

No, it is just a misconception that it is called the "idle screw" since it has a direct impact on your idle.