Anyone wanna help me tune out my high idle? Total Newbie

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sgtbilkodle
Posts: 2
Joined: Sat Mar 29, 2014 10:25 am

Anyone wanna help me tune out my high idle? Total Newbie

Post by sgtbilkodle »

1988 Chevy R20 with (1991) 7.4L (454)
It idles too high
Vacuum leaks ruled out.
I have datalogged a cold start, to full temp then short drive.
IAC counts around 50ish at idle and up to 110 at 55mph.
Interestingly, spark advance stays at 0.00 the whole time (I verified that the electronic spark timing bypass connector is connected)
I have TunerProRT, C.A.T.S. Tuner, Burn2, Moates ALDU1/CABL1, netbook, G2 adaptor installed in ECM, spare chips to burn new bins and datalog but not sure how to post the log here.
JP86SS
Posts: 218
Joined: Thu Apr 22, 2004 5:49 pm
Location: Strongsville, Ohio
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Post by JP86SS »

Could try reducing the Park position of the IAC.
that may be setting a minimum starting point while warm running.
do a IAC reset and reset your TPS as best as you can.
You may have difficulty starting after the change due to added vacuum load when cranking due to less air. Tends to crank slower with less throttle opening.
there may be cold and warm park position values.
Something to try.
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sgtbilkodle
Posts: 2
Joined: Sat Mar 29, 2014 10:25 am

Post by sgtbilkodle »

Thanks for the suggestion. I've done that, set IAC start to 50. Have my desired idle down to 550 just so I actually get 750 out of it. Still starts out high when cold. If anyone is interested in reviewing my log file, i could send it along with the bin. That might help you see how it's running and what parameters are set...
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