Idle Tune issue

[msassman]

Have been tuning a Cam Upgrade on a 2000 Camaro SS. Cam is a Texas Speed Tsunami V2 235/240 .629"/.615" Camshaft with Rhoads variable duration lifters. I adjusted the MAF and VE tables and got them pretty close. Couple of issue seen while tuning, I get rich readings when I get off the throttle while driving, and it drifts lean while idling. Is this normal? Also after tuning I am getting surging while idling after startup when warm, but not after driving. So Just after a warm start when I first start driving.

I attached maf tune and log, ve tune and log, drive and idle with all adders enabled, and the corresponding tune.

I have the wideband wired into the egr on the pcm, used the calculation from the vendor which was off, I assume from the resistance in the wires I ran from the console to the pcm, but have corrected for that with a modifier. Lambda of 1 matches pretty close on both. Plan to move it when I can but the data is accurate from what I can tell.

Any help on these issues appreciated.

[kingtal0n]

Rich on throttle lift- adjust your DFCO entrance, "fix" the upper rows (high vacuum area) of the VE table, and play with the fuel-wall cling settings (forget what they are called) Its like port to wall evaporation time or something, for high vacuum regions.


Lean while idle and just after restart is usually a heat soaking IAT sensor. The way I get around this is I do two things:
1. variable resistor between the IAT and ECU that I Can dial by hand up or down, about 1000Ohms is enough to bring that 15.6's back into the 14.8 to 15.1 you desire at idle. I never use closed loop at idle for various reasons, I prefer 14.8 to 15.2 a/f for clean new looking plugs and ideal economy anyway.
2. Re-tune the IAT calibrations slightly so that it takes a bit more temperature to raise the IAT (in other words, desensitize the IAT calibration to slight heatings)


Lean after hot refire and when putting it into gear there is a fuel adder table made for this. PN to Drive enrichment table or something. Just add fuel here and set the delay so that it hangs around long enough for you to get moving and bring that IAT back down to normal.


Other suggestion:
Relocate the IAT sensor to before the throttle body, and use a plastic washer to insulate it from the heat of the tube in which it is installed

[msassman]

Thanks for the reply and sorry for the delay responding, recovering from spinal fusion surgery.

You mentioned not using closed loop at idle, I don't see where that can be set for idle, just on or off.

Also could I be getting false lean reading at idle from the overlap sucking air out the intake? This occurs even when engine compartment (IAT) is cooled off.