Idle hangs for a few seconds when coming to a stop

[DaddySS]

I went through a complete rework of the 02 OS and 00 tune and the results are good but I have this annoying idle hang for a few seconds after I come to a stop which I suspect is also making it slow to decelerate. If I change the TC and TF airflow and or decay it's better but still hangs when I come to a stop and slow to decelerate. It hangs by about 100 rpms. I didn't have it when I was running the 02 settings so I just think I'm missing something. I went through the idle tutorial but don't see anyhting that causes this? Thoughts?

[SSpdDmon]

Double check ALL of the TC and TF settings to ensure they're equal to the old tune. TF Multiplier=1, TC MPH on/off, etc. The easiest thing to do is to log them. Log the IACDES_B, Throttle Cracker and Throttle Follower. You'll see where it's coming from.

[DaddySS]

I probably wasn't clear. A few weeks ago I took the 2002 base tune running on the 2002 OS , aside from the diags, injectors, speedo etc, and using the throttle cracker from the 00 tune. It ran well as far as drivability is concerened, accelerates smooth, no KR, decelerates nice and virtually no surge or bucking at all but not as strong. This week I reidi the full 2000 tune on the 2002 OS except for left the trottle cracker as it was on the 2002 tune because that worked well and now it has the idle hanging for a few seconds when I come to a stop, doesn't decelerate as well and cruises a little bit when I get near 2000 RPM. I then tried the throttle cracker and follower tables from the 02 tune, helped a bit with deceleration but still have the hanging idle.

[SSpdDmon]

I probably wasn't clear. A few weeks ago I took the 2002 base tune running on the 2002 OS , aside from the diags, injectors, speedo etc, and using the throttle cracker from the 00 tune. It ran well as far as drivability is concerened, accelerates smooth, no KR, decelerates nice and virtually no surge or bucking at all but not as strong. This week I reidi the full 2000 tune on the 2002 OS except for left the trottle cracker as it was on the 2002 tune because that worked well and now it has the idle hanging for a few seconds when I come to a stop, doesn't decelerate as well and cruises a little bit when I get near 2000 RPM. I then tried the throttle cracker and follower tables from the 02 tune, helped a bit with deceleration but still have the hanging idle.

Then, I'd tweak the delay/decay rates. Log the stuff I mentioned above and you'll know which one to go after.

[redhardsupra]

sounds like it needs a RAF adjustment

[Doc]

I'm with both Jeff and Marcin. As long as the RAF is good then, with the conditions you described then, the delay/decay rates are where I would start.

[DaddySS]

OK, I'll take a look at those and let you know what I find.