[Formulajones]

Originally Posted by HWYSTR455

One thing that helps is cracking the throttle blades a more, especially on larger displacement engine, that way the IAC doesn't have to 'work' as hard. Target idle compensation for IAC is 5-7%, but it will creep some after full heat soak.

Obviously, you need to do a TPS autoset after any throttle blade adjustment.

.


.

Yeah, basically what I've had to do for now to sort of fudge it, is to set the idle screw while in neutral until I have zero IAC, so that when it's in gear, it gives the IAC more room to open and maintain the idle. There are instances where it would sometimes just peg the IAC in gear and then slowly idle down and die.

It's been a fine line of adjustment that has been a real pain on dad's engine. On my engine (110 cubes smaller) it was a piece of cake.
I really think the IAC just needs to be bigger and I'm almost certain a couple of small holes in the throttle blades would help but mention that on the holley forum and they have a fit LOL.
For what it's worth, the HP 950 that was on the engine came out of the box from Holley with all 4 throttle blades with holes just for this purpose and that thing would idle at 750 rpm all day. This engine really likes a lot of idle air, and fuel.