I'm trying to get my '90 C4 corvette to run correctly. I've been having to drive it in open loop set for 27lb injectors lying to the ecu because it's really running 32lb injectors. I did that because for some reason I had to max out the VE tables to get the AFR's close to being right when I had tunerproRT set to 32lb. Telling it 27lb injectors adds more fuel to all the maps everywhere and so allowed me to lower the cell numbers while still getting goof AFR's. I think the issue with that is the ECU now removes too much fuel in closed loop because it thinks it's running 27lb injectors.

So today I started it up and it runs about 13.5 AFR as it warms up and I had closed loop turned off as I always have to run it that way. If I try to let closed loop operate the engine runs so lean it is un-drivable. I tried setting the ECU back to 32lb and raising the cell values but had no luck still lean. So next I tried an experiment, I set it to the factory Bin with 22lb injectors and VE maps, in open loop it was very rich 10's as expected. However in closed loop still 17's or leaner! What's going on?


I also suspect changes in weather are messing up my tune. Last night I had to remove -4 from the 80-100 kpa cells to lean them out
to achieve 13.0 AFR at wot. But today during the heat of the day the whole map was too lean once the car was warmed up in open loop. I need better consistency. Is there an air temp map or something to adjust for air temps in tunerproRT? If so will that take effect in open loop? I'm using the $8D mask.