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Thread: Cold Start Issues! Please Help!

  1. #1
    Tuner in Training
    Join Date
    Nov 2010
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    40

    Cold Start Issues! Please Help!

    Hey guys. I have a 2001 Pontiac Grand Prix GT, with a SS M90 kit (top swap), as well as a VS cam, headers, cold air intake and 2.5" cat-back. I've been trying to get it tuned up, but I'm still having issues. When I start my car in the morning (or after it's been sitting a while), it acts very strange. The RPM hunts a lot, and my wideband will go very lean at moments. I've also noticed my IAC values very high (around 250). When I start driving it, it wants to stall at low RPM. I noticed it the most when making sharp left turns. If I didn't keep my foot on the throttle, the RPM slowly drop, it would run very lean, and it would stall. Today, it did it while driving in a straight line. However, this time my car didn't respond to any throttle until I hit about 40-50%. The RPM wouldn't move. After about 2 minutes of running, it was completely fine. I'm wondering what I need to change? I've already raised the idle RPM, it hasn't helped. Is there any tables that relate to ECT/cold start that need to be adjusted for my cam?
    Last edited by Bedwards; 07-26-2011 at 06:17 PM.

  2. #2
    Tuner in Training
    Join Date
    Nov 2010
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    40
    It runs perfect in open loop during startup, but as soon as it goes into closed loop, it runs like crap for 2 minutes or so. After it's warm, it is completely fine. I don't know what to do. I also noticed that immediately after startup, my timing advance is very low for a few minutes (6-8 degrees or so). Is that normal?

    Here's a copy of my tune.
    Last edited by Bedwards; 07-28-2011 at 08:00 PM.

  3. #3
    Tuner
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    Mar 2004
    Location
    British Columbia
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    I've had this on SSM90 top swap cars.

    Easiest solution is extend the open loop cycle to 104*F or 40*C.

  4. #4
    Tuner in Training
    Join Date
    Nov 2010
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    40
    I will give that a try. Thanks man!