Weird IAC problem - need some help

talbotdd

New member
OK here is the issue I am having and I am wondering if you guys could help me out:

I was having a problem with a bad idle and an off idle stumble so I replaced the IAC and cleaned all the passages. I adjusted the idle down to where the datamaster was reading 20ish and I went through the reset procedure and pulled the ECM B fuse and it ran great.

Problem is that each time I shut the truck off and re start it I have a higher idle and the same off idle stumble again. The IAC numbers change (closer to 40-45) and I have to go through the reset procedure to bring them back down. I have to do this each time I shut the truck off??? Each time I reset it it brings the IAC count down to 20ish until I turn the truck off again and it goes through the same routine.

How can I get the idle and stumble fixed for good without having to reset it all the time? All the other #s on datamaster look good - vacuum, fuel, etc.

Any ideas?

Thanks in advance,
Dustin
 

SBNova

New member
Re: Weird IAC problem - need some help

Whats your TPS voltage at idle? Maybe it needs to be adjusted.
 

talbotdd

New member
Re: Weird IAC problem - need some help

my TPS voltage was only .36 but I adjusted it and got up to .45 and still no change
 

SBNova

New member
Re: Weird IAC problem - need some help

I think its supposed to be .57 volts. I doubt it will make much difference, but you might as well make it right before moving on to the next step.

Idle speed is also dependant on engine temp, battery voltage and IAT (I think IAT's).. Make sure the ECM reads the those seneors correctly too.
 

talbotdd

New member
Re: Weird IAC problem - need some help

Thanks for the replies. How would I adjust my TPS to get a higher number? I have moved it as much as I can and I can only get .45- should I enlarge the holes so I can move it further?


-Dustin
 
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