Hello to All
I'm Raul from Spain, I have a customer with a Corvette C6 (LS7) with high Cams and high compression piston. This customer send to US (yes the car, not the engine) to be tuned. THis tuner did the engine and the tune file. when the car returned, idle was around 11.8 AFR and 1000 rpm to have a stable idle. Too Rich i think, i saw cars like this with 13.5 or 14 AFR idle
4 month ago the idle went to 10.1 without any reason, this customer checked everything on the car, changing lambda sensors, cats and the idle still is there. he called me this week to check the car with HP tuners and see if something is wrong. I was all the afternoon checking and modifing tables but nothing changed. here you have the things i did:
-Move the ECU to open loop.
-edit MAF table, i moved to stupid values to see any change?( from 17 g/s to 4g/s)
-edit VE table, same as maf (from 60 to 10)
-edit MAF table at Cranking, nothing
-edit lambda demand (14.7)
-edit lambda table rich/lean voltajes
Maf values are ok, if i change the table i can see the same frecuency gets me different g/s. Map sensor Works correctly too. Checked with engine stopped and reads atmosferic pressure, with engine started, reads about 65 kpa
if i put the car in closed loop, i can see the short and long trim go to 10.1, and are near to 0% correction at this value, if i modify the Maf table, closed loop (long and short trims) starts to add fuel to go again to 10.1. Car has some DTC deleted like, lambda, Throttle, AC, Air pump etc, like a race car.
For me the car looks like it is in limp mode and goes to a very rich escenario for safety. Not sure if could be posible with this ecu.
Any idea about this?