help with low iac numbers
TECH Addict
Joined: Dec 2010
Posts: 2,610
Likes: 4
From: Maricopa, AZ
In this log, were you idling in gear? If so, everything looks good! The IAC counts are a little low, but the AFGS looks right on par for your idle RPM. I'd say you probably have the TB blades open a little bit or maybe someone drilled holes in them before you bought it. But, it's nothing I would worry about. It would only need to move UP from where you're at. Turn on the A/C (if you have it) and you'll likely see the idle remain, but the IAC counts go up.
That and you're a little rich, but nothing that the BLM can't (and did) trim out. You could easily adjust that out if you wanted too though. Nothing worth fussing over.
Is it still burning your eyes rich? If so then you'd want to address that with O2 target (swing voltage IIRC), but you'll want to confirm that the O2's are targeting the wrong AFR before you adjust that with a Wideband. But, if you are not running a cat(s), it may seem rich even though it is not.
That and you're a little rich, but nothing that the BLM can't (and did) trim out. You could easily adjust that out if you wanted too though. Nothing worth fussing over.
Is it still burning your eyes rich? If so then you'd want to address that with O2 target (swing voltage IIRC), but you'll want to confirm that the O2's are targeting the wrong AFR before you adjust that with a Wideband. But, if you are not running a cat(s), it may seem rich even though it is not.
Last edited by hrcslam; Dec 13, 2015 at 04:52 PM.
Launching!
Joined: Aug 2013
Posts: 205
Likes: 6
If so then you'd want to address that with O2 target
usually burning your eyes rich is actually lean misfire due to the ecm trimming out too much fuel with corrupted o2 readings at low airflows, high cam overlap, and reversion making the maf readings way off...
adjusting filtering/delay timing/strength at low airflow can help a bit
Thread Starter
Teching In
Joined: Jun 2015
Posts: 16
Likes: 0
The engine has no ac no cats and a manual transmission. The butterflies are closed tight, not sure about the holes but dont remember any??? Thanks again for the help, dont think wide band 02's are in my future, heaver axles and lockers well thats a different story. I might work with the tuner and ask about the target of the 02's.
Thanks for the help I got the miss fixed and its getting decent mileage again.
Stevo, the engine is stock... no high overlap. Wide band 02's have been in the back of my mind for years maybe after im done spending the next million on the build.
Thanks for the help I got the miss fixed and its getting decent mileage again.
Stevo, the engine is stock... no high overlap. Wide band 02's have been in the back of my mind for years maybe after im done spending the next million on the build.
Thread Starter
Teching In
Joined: Jun 2015
Posts: 16
Likes: 0
So I have to say the issue was a exhaust leak that you could not hear by ear, or it wasnt very loud. I pulled the passenger side header to find exhaust tracers out the gasket. Picked up some new ones and the split trim problem went away. The low IAC numbers didnt change although it runs better its still a little rich. Will work on that next.
Thanks for the help everyone.
Thanks for the help everyone.
