By some reason the rpm jumps up from 800 to 1500 when going from neutral to drive. The test I made was done with the vehicle lifted up with rear wheels spinning free in the air. It seems to me that the desired airflow jumps from 4.5 g/s to 9.5 g/s when shifting to drive. I've looked through the tune but cannot figure out what could cause this!? Please see attached tune and log.
Many thanks in advance if anyone could give me a hint of what the problem might be.
It may be under Engine-Idle-Airflow-Idle Airflow- then you can see the two rows Gear and P/N, see if your Gear airflow numbers are a bunch higher than your P/N and you can bring it down a little. I think you want to make sure to adjust it relative to your coolant temperature your seeing the problem at of course.
What happens if you apply the brake instead of allowing the wheels to free spin in the air? The wheels free spinning is not what happens on the street where the engine would be fighting the brake or driving the car forward and therefore require more air.
Thank you both for your input. The reason was that the idle airflow was set to high which the ECU compensated with STIT of -4.5. When I shift do drive the STIT jumps to 0 (by some reason?) which resulted in 4.5 more idle airflow when in drive. I subtracted 4.5 from the idle airflow tables which gave STIT of close to 0. When shifting to drive the rpm remains the same which I was aiming for. Problem solved!
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