Challenges setting minimum idle air.

[scorp508]

Originally Posted by XfireZ51

Mine is ported and cammed as well. U want to set the idle rpm just below where u want it to idle normally so that the IAC will intervene and keep it from stalling out.

It idles smooth at 850 once warm and I went 75 below that with the throttle stop screw. Should I bump that up to say 800-825? I wasn't sure just how quick the IAC can react.

U should also work on timing and fuel tables to smooth things out and avoid any choppy transitions of both.

I'll check them again and see what it's like down there.

Also, the throttle follower tables should reflect the IAC steps u r actually at for idle.

I don't believe these follower tables in the XDF I'm using.

[XfireZ51]

The way to set the IAC is after u have it idling just below ur desired idle, say ALMOST stalling, IOW once u have set ur idle just below where u actually want it, connect everything, restart w diag tool and now see hiw many IAC steps u have for ur desired idle. I shoot for something like 10-15steps. If its above that, then open the TB, below that close TB. The point is u want to achieve as little ECM intervention necessary for the motor to operate. IAC reaction is also something that can be modified slowing it or speeding it up.
I like to set my IAC when fans are running due to the extra load so as to give me an extra margin.

[scorp508]

I gave it another try yesterday while prepping the car for Carlisle and was able to get the IAC steps to 16 at warm idle with fans on.