Now that the weather is getting hotter I seem to be having a problem idleing in gear. It is really bad with the a/c on. When you look at the iac it is in steps. When you go up does it open it more? Also why does the stock app for the 92 firebird only raise the idle 12.50 rpms. I tried to put it at 150 because I am going nuts having to put it in neutral everytime I stop. By the way it didnt help it still tries to stall. This was a car that was perfect before it started getting hot(I live in florida).I also tried bumping up the idle from 850 to 950 and it didnt go up just struggles more. I have managed to take a car getting 8 mpg and get 20 but cant get it to idle with the a/c on. I have a very good understanding of the ve tables and how they work but other than that I am alittle lost. PE also has me alittle baffled. Is there a good site that explains the 8d alittle better than the tuner pro manual? any help would be great. Sorry about changing the subject but figured I might be able to kill two mustangs with one formula (birds and stones) haha
thanks,
Joe
92 formula firebird 383 12.5 comp
224 230 560 lift.comp extreme grind 4deg retarded. stock ported vette heads(1988)
stock ported siameesed intake .tpis runners. 30 lbs injectors(accell)
700r4 3000 tci 10inch converter 3:42 gear
390@tires 510 torque
last time out 7.60 @96 in 1/8th terrible 60ft. 2.10

 

Might try reducing the number of seconds required for RPM error when the IAC is learning when the A/C is on.
Location L838C in AUJP (if that's what your running)
Never messed with it myself but reducing the stock setting of 4 seconds may help recover before stalling. There are a couple of items concerning the IAC A/C tweaks in that area of the calibration.
L8389 is "Max learn steps" stock is 32 steps
L838A is "min learn steps" stock is 10 steps
L838B is "max steps per learn event" stock setting of 5 steps. (try 10 ?)
L838D is "PK/Neut gain multiplier" stock is 0.50
The multiplier may need to be reduced if the learning amount is increased. Seems to me that without reducing the unloaded gain there could be rpm flare ups or hanging high surging at the time interval for the RPM error.
Like I said, I've never messed with these and have not heard of anyone doing so. Give them a try and see if they help.
Be sure to check the indication that the clutch is on is actually getting to the ECM.
Also the idle is limited in gear to 800 rpm in hardcode. It can be changed easy enough if needed. Check in the tuning guide for that one.

 

I didnt realize that the blades were to far closed and the iac was open all the way just to acheive the 850 idle so when the a/c came on it couldnt add the extra rpms due to the maxed iac.....oops...where is this tuning guide you are talking about?
thanks,
Joe

 

In the stickys at the top of the DIY-PROM board.

 

found it thanks.....
Joe