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Thread: Interesting idle ? I could not find anywhere

  1. #1
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    Default Interesting idle ? I could not find anywhere

    I've noticed that when I first start the car on cold start it idles low and rough. Ok, figure this is a problem in the idle section and can address it later. After it starts to warm up it 's good at 950-1000rpm and EQ stays at 1.0 almost constantly.
    I then realized that it does the same after a hot restart so I decided to log the hot restart. Seems the PCM is commanding 12.96 AFR for about the first 2 minutes where as the car idles around 400-600 and almost shuts off. At the initial fire up actual AF is 17 for about 10 seconds then it falls to the 12-13 range for this first 2 minutes or so.
    Why would it command 12.96 breifly even on a hot refire and what would need to be adjusted?

    Thanks in advance
    Shawn

  2. #2
    Unknown Zone TAQuickness's Avatar
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    Anytime you start the car, you start in open loop. ECT determines how long you will remain in open loop. So, in other words, try looking at your open loop fueling and adjust as necessary.

  3. #3
    Lifetime Member SSpdDmon's Avatar
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    The 17AFR you see right after start up is the WB warming up. If you hooked up the LCD, you should see it blinking. Once it stops blinking, it starts reading the 13AFR you mention. As for idle, have you logged your RAFPN/RAFIG yet? I've tuned a couple 23X/23X cars and have no issue with the richer AFR on startup. Sounds like you might just need a little more desired airflow.

  4. #4
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    Thank you for the replies. With the help of Black02SS idle is great now. Everything is working out great.

  5. #5
    Guess who's back!!!! Black02SS's Avatar
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    Glad to see it all worked out for you.

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