MacMan

iTrader: (19)

My Evo has developed a weird symptom. I'm tuned open loop 24/7, so my afr map has around 17 afr for idle. When I start the car, I log it and the ecu sees the proper 17afr in the map, which puts me at 15.5 on my gauge ( perfect )

Here's the problem... once the car warms up, it's as if the ECU stops seeing the proper number in my afr map.... same 17 in the map, but now it says the ecu sees it as 13.8afr instead, which is making me go really rich (12 flats)

It's none of the usual suspects.... boost/exhaust leaks, vacuum/ground issues. I'm 100% good, it's def something else. So guru's, what could cause the ECU to stop seeing the proper number in my afr map and see it as 3-4 full points lower once warm, but is perfectly fine when warming up. It also kinda just started to happen out of the blue. WHen braking, i would notice the idle dip down 3-500rpm lower than it's suppose to, afr's fall down rich... would never die and would eventually get it'self right. It doesn't seem to affect the car while driving... my cruise afr's are on point.

I checked my IACV, pulled it out and turned the car to ON. It clicks and moves, albeit not much movement. I cleaned it with carb cleaner and reinstalled... still happens. TPS sensor reads right at no throttle and 100% at WOT. I'm on speed density, my OMNI 4 bar is less than 3 months old, would like to think it's still ok. ANything I could log to try to figure out an answer or SOMETHING!?!??~?

ReaperX

iTrader: (5)

How long ago were you tuned and what is the temperature difference from when you were tuned to current?

MacMan

iTrader: (19)

I'm CONSTANTLY tuning this thing.

ExViTermini

iTrader: (25)

What do the ECT and IAT say?

MacMan

iTrader: (19)

Am tuned using the fuel temp sensor so no IAT, and pardon my ignorance but I don't know what ECT references.

todd6027

iTrader: (10)

engine coolant temp

MacMan

iTrader: (19)

In the log I just looked at... 190-210

MacMan

iTrader: (19)

was a bad map sensor.