6.0 LQ9 stock other than a holley split intake 4150 style with a EBAY special FAST 4150 throttle body, headers, exhaust in my 1972 Chevelle. I have HP Tuners.

SDCL, cable

Ive had trouble with my IACV counts going to zero since I did this swap a couple weeks ago.

Engine idles fine, maybe a little low in RPMs, engine runs great, but my IACV counts stay very low even while cruising and like to sit at zero at idle.

However I have had intermittent hanging idle and "cruise control effect" problems as well.

I took the chevelle out last night and it was running great. I went to get gas and when I fired it back up the idle wanted to hang and the IACV was making a sucking noise.

So this morning I took off the throttle body, cleaned everything, blocked off all PCV lines to rule that out as a possibility, double checked connections and vacuum leaks.

Fire up the engine and my IACV counts are in the 80s. I thought great finally some progress. I opened the blades slightly to get the counts down. Fired it up again and idle was way high. Closed the blades back up to get the idle down but now my counts are back to zero.

Is there anything in the tune that could be causing this? I dont know how I could have high idle counts and the zero idle counts even though I closed the blades back up and all other things unchanged.

IACV is new and it is the recommended valve from FAST.

 

Part of it is probably the EBAY throttle body.

Have you logged STIT and tuned the BRAF table any?

If the IAC counts are 0, you either have a vacuum leak or the throttle blades need to be closed some.

 

I completely closed the throttle blades. I have logged STIT but im not sure what they should be at. I have not touched the BRAF table.

I'll post back later with my tune and STIT data.

 

Log LTIT also if you haven't turned the idle adaptives off.

 

Well now mysteriously my IACVs are now in the 160s....I dont know whats going on with it. It logged LTIT but I didnt see an option to log the STIT channel...