Help With IACV Counts
Thread Starter
Launching!
Joined: Mar 2012
Posts: 299
Likes: 21
From: Phoenix, AZ
Help With IACV Counts 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.
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.
Last edited by Smitty454; Sep 25, 2022 at 01:03 PM.
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.
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.
Thread Starter
Launching!
Joined: Mar 2012
Posts: 299
Likes: 21
From: Phoenix, AZ
I'll post back later with my tune and STIT data.
