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View Full Version : Idle Air Controller Trouble Shooting - need help

QB93Z
05-08-2009, 03:45 PM
I am working on an idle rpm problem on a 1994 LT5. The idle speed is about 580 rpm and is just a little too slow. I connected a Tech 1A and used the Idle Air Controller (IAC) adjustment function to try to raise the idle speed. The idle speed did not change.

I used the Tech 1A on my 1993 and was successful at raising and lowering the idle speed, so I know that the Tech 1A and the procedure work.

I swapped the IAC from my 1993 to the 1994 and repeated the change idle procedure using the Tech 1A. I can successfully raise and lower idle speed in the 1993 (with the 1994's IAC installed) but still cannot change idle speed in the 1994 (with the 1993's IAC installed). I believe that this eliminates the IAC as the problem.


The FSM trouble shooting procedure for the IAC requires the use of an IAC Driver test device and an IAC Node Light, neither of which I have access to.

Questions:
Does anyone know where I can get an IAC Driver and IAC Node Light test kit, Kent-Moore, Inc J37027-A?

Any other suggestions about solving this problem?

Thanks,
Jim
GOLDCYLON
05-08-2009, 03:52 PM
Jeff Flint ?

I need to learn how to do this mine needs to be lowered to about 750
secondchance
05-08-2009, 03:59 PM
Hi, Jim,

Upon quick google I found these websites. 2nd web has what they call noid light.

http://www.rinda.com/RamJet/ramjet.htm

http://www.usatoolsinc.com/index.asp?PageAction=VIEWPROD&ProdID=15875

Good luck!
Aurora40
05-08-2009, 04:37 PM
What does the Tech-1 say the desired idle is? Does it appear to be changing the IAC counts?

What I mean is, is the ECM trying to raise the idle and is simply unsuccessful? Or is it not trying?
QB93Z
05-08-2009, 05:41 PM
What does the Tech-1 say the desired idle is? Does it appear to be changing the IAC counts?

What I mean is, is the ECM trying to raise the idle and is simply unsuccessful? Or is it not trying?

Good questions. I will get a readout of IAC position (IAC counts) before and after an attempt to change idle speed. This should tell me if the ECM is sending the signals. I will have to wait until the owner brings his 1994 Admiral Blue up here again.

SC: The websites are great. I will probably order some items.

Thanks
Jim
secondchance
05-08-2009, 06:01 PM
Glad to be of help.:cheers: