Setting IAC With TT Chip

[Brutal Buick]

I figured it would be quicker to post here than to email Eric personally. Anyway, I am having a problem with my IAC counts dropping to 0 after installing a new TT chip. I got a response from an earlier email and Eric told me to adjust the IAC to raise the numbers. I know you are supposed to do this when the car is in closed loop ... How do I go about this if the chip no longer goes into CL ?? Is it OK to do in open loop??

Jamie

 

[87NAT]

Erics chips go into open loop idle even when the car is warmed up. Make small adjustments with the set screw to open the throttle blade till the IAC numbers are between 5-30 or so. After each adjustment let the car idle for 2 minutes so the ECM can hunt down the idle. Shut off the engine and restart and see where your numbers are at. You may have to do this a few times to get it right. Remember to check your TPS values each time because they will be affected by IAC settings.

If you cant get any number higher than 0 then you have unmetered air getting into the motor somewhere else i.e., vacuum leak. What are your BLM's at idle?

 

[Brutal Buick]

Thanks for the quick response. I'll try to get it set this weekend. My BLMs are 142 at idle

 

[87NAT]

You probably have a vacuum leak. Dont waste your time trying to set the IAC till the vacuum leak is fixed. The ECM does not need the IAC if its getting unmetered air from somewhere else to idle the motor.