Strange Idle after PCM Tune? IAC Related?

[Hagancue]

Just had my PCM tuned by PCMFORLESS and I am very happy with the result. It realy runs great and gas mileage increased about 10%. I do have one odd thing that started when I installed tyhe PCMFORLESS tune(clear step change). The engine comes down to idle very slowly when you coast down to a stop (about 4 or 5 seconds) and if you back off the throttle to coast while driving, you can feel it still pulling. When driving or at a stop after coast down it idles at about 1500 to 1800. After about 4 or 5 seconds in either case, it comes down to a normal idle. It does this most times, but every now and then it will come down to idle right away. No other drivability issues at all.

I have a 52 mm Holley, and all regular bolt-ons. Talked to Bryan at PCMFORLESS and he says that I am not the first to notice this and that he is aware and working to troublshoot. I believe that smoething in the IAC logic/function is whacked. It seems like when it is running in a certain cell, that there is a scaling problem with the default size of the moves that the IAC is commanded. When this does not work it adjusts incrementally until idle is reached???? When in anouther cell it is happy with default moves and works normally.

This is my uneducated guess. Anyone have any ideas on this? Similar experience?

Thanks in advance,
Bill H

[Hagancue]

TTT. Any Help here?? Thanks,

Bill H

[carl97ss]

I had a simular issue w/ bryans program. keep working with him and he'll get it figured. my works well now. I have a ported 52mm factory TB.

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'97SS, More Performance 396, AS&M cold air, Grotyohann LT, SLP 2ODL muffler, Magnacor, PCMFORLESS PCM, LS1 twin piston calipers, KVR crossdrilled and coated rotors, SLP stage II w/ KYB AGX, 6M, Star Stage II.

[Hagancue]

Carl,
Thanks - I;ll keep talking to Bryan.

Bill