What Is Wrong With my Car?I get IAC Counts set and warm up it Goes to Hell!

[Pro Mouse]

Ok on my 408 with a 90 MM Fast Intake ,TPIS 90 MM TB with NO HOLE,244 [email protected] cam,I get my Iac counts down to where I want them Get effective Area set ,Idle Air real close and the when car Idles for 20 minutes or so coolant temps are in the 190's The Damn thing will start Idling High for no reason ,My IAC Counts disappear and My Desired Airflow cuts in Half of what it was before.What Can Cause this?My Thoughts are heat throttle body expands and lets more air flow in,Logical?
Thanks

[Google]

no.. your IAT is going up and the fueling will change.. the pcm will try to lower iac counts.. would need to see a log with everything in it.. is raf or base idle airflow adjusted or is it higher when ect is 190ish?

[Pro Mouse]

No my base airflow is lower as motor warms up ,I am commanding it 1.12 at this coolant range which is right until it runs there for about 20 mins or so then Desired Airflow drop to .6 to .5's ,engine is running leaner as well.But my wide band isn't hooked up to HPT,its mounted in the car on a pillar.Could this be a vacuum leak?

[Google]

yes it could be.. would need to see your current tune to know.. when dealing with airflow it is best to use grams second.. right click change units to g/s..

[Pro Mouse]

Yes I covert them to grams/sec I keep it like this so I can actually see my coolant temp.If I pump the brakes in park my RPMs do come up 100 to 200 rpm.But what would be leaking and why does it take so long to kick in?

[Google]

need to see your tune..

[Pro Mouse]

Oh ,I forgot to say that after Idling for that long ,Also using the gear selector made it start idling a little higher also ,my Idle in gear rpm is set the same as my Idle in park rpm.

[Pro Mouse]

ok will post tune later tonight ,I am at work

[Google]

ok, might not be back online tonight or for a few more days.. on the road tuning in Cali then on to OR. but when i get a chance I will look at it..

[Pro Mouse]

Ok Cool Google ,Also I forgot to mention that my Idle rpms are very unstable have been since this engine.it will fluctuate 100 rpm

[Google]

prolly airflow and ve needing tweeked..

[Pro Mouse]

Ok here is the log that you can see when Desired airflow goes down.Sorry took me so long help wife get ready for Holidays haven't had any time to play with car.Ba HumBug LOL

[Pro Mouse]

Now the Tune you wanted to see....Thanks

[Google]

ok, after looking at this log and tune.. I see iac vs effective area is close.. make the changes in the picture to the effective area shown in the attached labled "change".. this will bring the iac vs effective area closer.. also after this you will need to log a cold start to first fan kick off.. no gas pedal, just start logging, start engine and idle.. the base idle airflow or (RAF) is off.. this can be seen as the effective area is close and the stit. and ltit's are adding/subtracting airflow.. also your raf is in the 11.00+ g/s in gear and in park it is in 5.00g/s.. yet dynamic airflow (actual airflow) is right around 9.00g/s.. so would need to see the cold start log..

also I am not able to see afr or trims.. if ve is not tuned correct and or maf is not tuned correct.. no point in adjusting the airflow tables as dynamic airflow will be wrong.. so need to log afr or trims in the table display..


with raf having a big swing fron park to gear.. this will cause idle issues as you discribed in your other post.. the higher the raf the higher the idle speed will be.. as the pcm is adding more airflow by way of the iac motor.. but you have to look at dynamic airflow to figure out how much raf to have..