IAC Reset Help

[Bob Hughes]

I need a little advice. My battery has been unhooked for about a month with my flywheel clutch issues.....I got it together and now the car dies during clutch in deceleration. I'm figuring iac needs to be set or adjusted again but I forget the procedure. If I unplug it while the car is running it immediately dies and struggles starting. It's brand new cobra iac. Any help would be appreciated.

 

[Bob Hughes]

I'll also add its custom tuned but I shouldn't have to reload the tune because the battery was unplugged right? I didn't know if the car needs some mileage to adjust and set sensors and that could be my problem

 

[wmburns]

It's normal for a car to idle poorly after a battery disconnect. The PCM needs time to re-learn correct idle trim values. This process repeats everytime the battery is disconnected.

To speed up PCM re-learning process, allow the motor to reach full opperating temperatue and idle for several minutes with your foot on the brake and the AC off. Repeat with the AC on.

If the slow idle problem continues, some causes include:

• dirty IAC valve.
• Vacuum leak
• Bad PVC valve
• dirty MAF
• poor cylinder power balance. Focus first on seconday ignition.

For more information:

http://www.allfordmustangs.com/foru...-dieing-idle-idling-rough-14.html#post2260649

 

[Bob Hughes]

Im pretty confident there is no real issue. Just got done building blower system with all brand new parts. It had no issue before I unhooked battery. I adjusted the iac through throttle body....seems to be good. Getting ready to go for a ride

 

[wmburns]

I adjusted the iac through throttle body....seems to be good.

It's generally not recommended to adjust the idle using the TB idle set screw. Why? If not done correctly it will appear to work until the next change in the weather.

Use an ODB2 scanner to cross check the IAC duty cycle is in the 30-60 percent range for best results.

 

[Bob Hughes]

I was actually given that information from Matt at performance evolution because my car ecm etc was not designed for the load of the blower on the motor. I'm running cobra intake throttle body into a eaton supercharger. I just couldn't remember the process off the top of my head.

 

[twogts4us]

I wasn't aware there was a way to adjust an IAC...?

 

[Bob Hughes]

Let me re-phrase.......adjust the idle as the iac can't counteract the rpm drop and load when decelerating. I got it all straightened put today