What are your IAC counts at hot idle? I bet they are at 0.

 

Make sure the TPS is at 0.5V or close to it, then turn off all correction adjust desired airflow down to suit, keep timing around 15-20 degrees. Adjust airflow till its commanding 15 to 20. IAC counts should be at around 40. If you have to run to much desired airflow and iac goes to like 140, then adjust the idle screw and slot the tps to adjust to 0.5v, or leave it as is and drill a bigger hole in it. After you get this right u can turn on the STIT tables, leave the learning ones off,. You can also minimise correction.

I went through this , this morning with HP tuners, I wish I had efilive to do it but still was OK, I got it all sorted to say the least. I basically modified the current tune and saved it under a new name "test idle", then once everything is done starting from tps to butterfly adjustment etc I then added everything across and was just a matter of running more airflow at cold start. IAC went back to 40. Once fuel trims were correct it idled even better i just had to put a touch of idle cracker in, idles now at 20 deg lead in CL cam is a 238-244-110+2, sad part was it needed a bigger fuel pump

 

heres the fresh scan

last 5-10 minutes is where it randomly goes nuts.

 

Looks like you have way to much RAF/startup airflow right at the beginning and by the time it warms up the IAC is completely closed. Your TB/blade opening is probably just too much (or hole too big). Try closing the throttle blade some more and work on your RAF to get your IAC counts around 60 or so at warm idle.

You're just getting too much air and the IAC can't compensate for it because it's already completely closed. Also what is your idle timing?

 

As I said on the first reply here, check the throttle body adjuster screw and close it some more

 

yesterday i was seeing 25* at idle but thats constant it doesnt surge it creeps then hangs.

the set screw isnt touching the stop.

i havent messed with teh tb in anyway. its as it came from tsp. oi this is getting frustrating

 

If the throttle is closed all the way and the IAC counts are at 0 I would be looking for vacuum leaks.

 

Well, you could lose a few degrees of idle timing but it wouldn't give you everything that you need.

You have ruled out vaccum leaks, right?

I interpret what you're saying about the TB that the blade is completely closed. Is that right? Is there a hole in the blade?

 

thats the thing, it doesnt act like tht

 

the propane test shows nothing

 

So where did your IAC counts/steps end up at warm idle?

 

they end up at 0

 

if your iac counts are zero then you have a vacuum leak.

 

Or the throttle blade isnt closed enough, too large a hole in the throttle blade (if you have one), pintle in the IAC is not seating in the idle passage, etc etc.

 

thats where im confused because they arent zero until a certain point and the idle doesnt creep up until a certain point. its not starting and going directly to the condition im asking about. also, running a little propane around the intake ports, map sensor, and tb hasnt gotten a response

 

hmm, maybe the stop needs a little massaging?

pinched o-ring ala oil pump type issue?

 

Once the IAC counts hit 0, the IAC motor will not be able to lower the idle airflow any further, hence the high idle speed.

 

Possibly. It is worth measuring the depth of the seat in the Holley TB & comparing to a stock TB.(The seat where the iac pintle extends to)

 

PTM 95mm

 

Check to make sure that the throttle cable has a little slack and not holding the throttle open - have seen that happen before with mismatched throttle bodies.

Bird