PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Idle high after coming to stop

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Old 04-02-2006, 10:01 AM
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Default Idle high after coming to stop

Right after coming to a stop, my car will idle around 1400 rpm, climbing to 1900 rpm before settling down to 875. Takes about 5 or 6 seconds to drop. I tried the HP tuners throttle cracker table suggested by WS6FIREBIRDTA00 but it didn't seem to make any difference. Any suggestions on what to try next?
Old 04-02-2006, 04:46 PM
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I have the same problem. The car had been dyno tuned after a cam install, but when coming to a stop after driving the revs climb for 5-6 sec and then slowly drop. I have always had that problem even when running the stock cam.
Even just revving the car, rpm seem to drop very slowly.
Could the IAC be at fault??
Old 04-02-2006, 06:10 PM
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Have you tried using the stock cracker/follower tables?
Old 04-02-2006, 06:19 PM
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Originally Posted by DrkPhx
Have you tried using the stock cracker/follower tables?
I can't say for sure as the first time I ran was with a mail-order tune. I doubt they changed the cracker follower tables so probably yes. All I have changed thus far is the cracker table. Would lowering the values in the follower table help?
Old 04-02-2006, 06:32 PM
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Each car is different. All of the follower tables on mine are set to stock values and the cracker table is actually less than the stock values. I would try and zero out the cracker table below 2200 rpms for sake of experimenting and see if that lessens the effect. If it does lessen, but still hangs, you're idle flow in gear may be too high.
Old 04-02-2006, 06:53 PM
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You can lower the values in the cracker table further and you can try to work with the throttle cracker decay rate to bring it down quicker.
Old 04-02-2006, 07:46 PM
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Since I had already reduced the cracker table values, I halved all of the values in both the P/N and In gear throttle follower decay tables. That seems to have worked.

Thanks
Old 04-02-2006, 08:14 PM
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when I shut off the DFCO this problem went away for me




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