I bought a tune from an experienced OBD1 guy years ago for my 3400. 40 or so cars also bought the same tune. But since day 1 I have been fighting rich readings from my o2...(stock single wire, then 3-wire conversion, and wideband). I just loaded the $A1_TPv5.xdf to do a little tuning and found that it is different than the xdf I was using with v4 back when I built the car.

My injectors are the 22.5lb Multec IIs stock with the 3400. Stock for the car was 16.7 Multec Is. I see in the old xdf the 0x6C4 was at 22.48lb, but the 0x6C6 in the new def is 16.71. Both are called injector flow rate lb/hr but they are in slightly different locations. Any ideas? In the xdf it is noted the 0x6C6 is for DIC/DIS calibrations only...but if so, where is the flow rate calculated for fuel delivery? 0x6C4 is noted as "injector constant for alpha-n idle" with stock being 16.7 and the calibration I have as 12.42?

I am confused. Looking for a little guidance. Thanks