I switched to the Ford LU80 injectors several months ago and have had driveability issues ever since. The injector data is good (as far as I know...), but its difficult to nail down fueling. During high vacuum decel (around 14inhg to 20inhg) the wideband slowly swings rich to settle around 11:1 AFR until I roll back into the throttle again to increase manifold pressure. Also, during tip-in, it goes momentarily lean, 16+ AFR. I have tried adjusting transient fueling by increasing the values a little bit, but it made no change. Another problem worth mentioning...I always have to hold the throttle down a bit on startup and slowly let it out as it idles. Otherwise the engine dies immediately after it fires up. I've tried all the normal tables, base idle airflow, STIT, timing, etc...no change. I think its still injector related.
I haven't been able to put a good tune on this thing because any work I do in the VE is just covering up what ever the error is. Pretty frustrating... Anyone seen/solved a problem like this before? Will upload a tune if necessary, just fishing for someone who has seen this before. Thanks in advance.