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Idle hunting / swinging while coasting down to a stop

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Guys i'm pretty new to tuning via computer vs an blade screwdriver and a ear.

Anyways i have an gen3 LS1 in a 98 Ponitac TA with a 6 speed with a pretty large cam (.525 230/240 with 106LS (GMPP stage 2 cam)). It was tuned by someone at a speed shop years ago.

The problem is when the car is warm and i'm driving up to a light i will place it in neural and coast down to a stop. Once i pop it out of gear the idle will swing and almost stall then catch itself and slightly rev up. It continues to do that until i get below 5mph then it seems to straighten out.

I have started at the air flow map and from the scanner i look a little low and i'm going to increase those to begin with. I'm just looking for advice on where to start.

I have uploaded the tune currently in the car and a short scan i was able to make while the idle was swinging.

Attached Files

check in your base idle set up I see it is all set to 0 when out of gear this could be a cause

Regards /ross

I'm not sure that would matter, The car is a manual transmission car.

Sorry I haven't got my laptop with me at the moment to check your tune, does your os have 'rolling idle airflow' maps? You should be able to add base airflow based on road speed with these. Try bumping it up (or turning them on if they aren't active already)

Dan, did you get your problem resolved? I have the same issue with my LS2 swapped into a 1959 GMC. I am curious if you did fix it, what you did to fix it.

I found the Base Running Airflow chart in my computer and increased the air flow between 180-200 degrees slightly. That helped the car, but i'll warn you to make small adjustments. I did too much the first time and the car wanted to pull through the brakes, it wanted to idel at 2200 rpm's while coasting in neutral.