Continuing to have issues with the car leaning out over time when on track.
Initially had made a thread about the car leaning out over time at idle, but unfortunately it appears to continue to do so on track as well.
Would appreciate any help or tips as to how to how to continue to troubleshoot this !
AFR leans out over time and could not replicate on a shop dyno (dynojet).
ECU, MAF, primary 02 sensor, wideband gauge and sensor, alternator, throttle body with sensors, coolant temp, air intake temp, egr valve, fuel pump, fuel filter, have been swapped in an out for known working or new pieces without effect. Smoked tested with no leaks.
Wideband is logged and close to dyno tailpipe reading so assuming it reads correctly.
Fuel pressure is logged and stable throughout the race.
Voltage doesn't appear to drop. (14v+ during entire race.)
After its last stop on the dyno at the track we set it up rich to make sure it wouldn't get too lean at the end of the race.
Not sure if related as this started only recently, but car also sometimes hangs at idle (1500rpm, then at some points drops back down to 850)
Attached a screen grab of the AFR log vs RPM during my last race this past weekend: green is second lap, red is mid race, and blue is last lap, all in middle of the main straight.
Coolant temp was around 190 all race.
Any idea what to try next ? Voltage drop across wiring somewhere tricking the ecu into leaning the car ?