Soda

I am unsure about a particular issue I have with my tune.

Every time I pull up from driving normally (never had a single issue with how it feels, no stuttering, no rough idle, always sitting around 14.7 at cruise and trimming) I see that under 1000rpm, injectors resume operation, the car over fuels at idle, wideband shows something around mid 13s AFR for usually around 15 seconds (can be 10 to 20 seconds), then it settles back to trimming without me doing anything.

The car is as follows.

Evo 9 GT (mag/titanium turbo) with < 10,000kms on engine.
2.5 inch TBE
standard airbox with K&N panel
slightly larger intercooler
98 RON fuel (all day everyday)
560cc injectors
AVC-R boost controller with boost holding @ 21psi

Tephra V7
MAF tuned
injectors @ 513 scaling and default latency
low/mid fuel trims within 2% +/-
wideband is matching cells in fuel table on WOT (yay!)

seemingly absolutely no vacuum leaks
no consistent knock @ load (9/10 pulls it has 0 knock count.. and sometimes what I'd say looks like shift or lift-off knock)

Take off feels completely normal without a problem.




I should add that the entire time it's adding the fuel the front o2 is reporting rich rich rich as you'd expect a normally functioning front o2 to do.

Even more details:
For all of the time @ +8% fueling and the time of normal trim the following is true:

• IPW sits @ 1.5ms
• ISC stepping sits at 22 dropping to 18 then rising again to 22
• timing @ 4* to 6*
• coolant temp @ 87C to 91C
• coolant temp scaled @ 81C to 84C
• tps @ 13.3 stable
• battery @ 13.4V
• airflow/rev @ 30 rising to 33 as it settles back to trim
• air flow Hz @ 25Hz

I thought that it was because my MAF compensation was out in some way at the two lowest hz readings, but it seems it's not as I have adjusted for close to 0% +/- trims with two different settings for MAF@low hz. The default scaling table is used only compensation has slight movements from stock.

My questions..

Is this in any way normal for anyone else?? Or can you think how to explain this behaviour?
What does the 'A-F Learning Inhibit Time v Temp' table I have added into the image affect? I ask because at normal operating temp it shows 14 seconds which might have some relevance?

Thanks all.

Soda

As a separate but related question.

Should the crossover point from low to mid trim be set just above idle or deeper into throttle??

For example. I idle at 25Hz (@13.3% throttle position) and have my crossover set as follows:

• low to mid -- 56.25
• mid to low -- 43.75
• mid to high -- 1587.5
• high to mid -- 1581.25

Obviously high is never going to be set and will remain at 0.
But does it make sense that I have the crossover from low to mid at 56Hz? This represents 20% throttle in my car. (as I understand it throttle % directly corresponds to MAFhz).

It just seems odd to me that other than anything but the lightest throttle response the car is always sitting in mid trim.

I know... I should just get someone to professionally SD it and be done with it, but it's not going to happen for a while and I'd love to hear people's opinions on this. I've seen some discussion on this before but nothing in great depth.