AFTRBRNR

Can anyone identify which parameter I should focus on to prevent stalling when in hot weather with A/C on. The car does not stall with the A/C on in cooler weather.

Could the warmer ambient temps cause my car to get too rich and die?

enoniam

Idle air flow and rpms are both controlled by separate tables. Each table has conditions for AC on/off, and whether in gear or P/N. For each condition the table sets air flow or rpm values by coolant temp. You probably want to look at the idle air flow and rpm values for the coolant temps you are seeing in warmer weather that you don't see in the cooler weather.

Also, the PCM's go into "idle" mode when the speed is below a few miles per hour, (although this speed can also be adjusted in the tune). At and below this speed the computer applies learned air flow trims to get the idle at the programmed idle rpm level. You didn't state whether it was dying when idling at just a couple of mph to 0 and/or at higher speeds. There is another table that makes adjustments to airflow when you lift your foot off of the throttle at the other than near 0 speeds. At these speeds the learned airflow trims are not applied but the values from this table are.

In HPtuners you can log at least some of the idle air flow trims so you can see if the learning is adding to the airflow in warm weather. If adding a lot there may not be enough "base" idle air flow to support keeping the engine running when not close to being stopped.

I hope this makes sense...

AFTRBRNR

Usually it stalls after I start up and the throttle hang lets go. Sometimes in stop and go traffic although not often, if I tap the gas with a quick deceleration it will tend to stall. I have adaptive idle disabled because it basically causes my car to idle at about 30 MPH and that's not good.

enoniam

What do you mean about it idling at 30 mph?

AFTRBRNR

If I don't touch either pedal, the car will build up to about 30 MPH. This is why I disabled the adaptive air control completely. Doing that, the car will just walk forward with your foot off the brake like it's supposed to.

enoniam

OK. First, turn the adaptive idle back on. That will help your stalling issue.

To correct for the idling up to 30 mph you need to check to see where idle control kicks off and on. Usually going above 3 mph turns it off and when off going back under 2 mph turns it back on. Should be on the Idle/Airflow tab if I remember correctly. These values control where adaptive idle is allowed to happen and will keep it from occurring above 3mph.

Then check the Idle Cracker table, also I believe through the Idle/Airflow tab. I bet you are going to find positive values here which is how the stock setup comes from GM. With a bigger cam airflow needs to be added at idle rpms, but not at higher rpms. This table is adding (or possibly subtracting) to the programmed Idle Air Flow, which if you have a cam was probably set higher than stock. You can probably get buy with setting these to 0.