ECU fuel mixture adjustment

XJ-S
1

Finally got around to adjusting fuel mixture on my 16CU 1988 XJS ECU that was super enhanced by Roger Bywater. Thanks Kirby for awesome write-up in the book.

Warmed up, open loop, both A and B were spot on at 1.9V

Closed loop, A bank fluctuated around 1.8V, B bank around 1.7V. so a bit lean.

I turned potentiometer exactly 6 clicks richer (it was dead center to start). A bank now around 2.0v, B bank around 1.9v. I could not get both to fluctuate around the same #, so erred on the rich side.

Is there an issue if both banks have different numbers? O2 sensors are new.

Thanks

2

They always have different numbers, usually farther apart than yours. You did good.

1 Like
3

I read this part of the book too.

Just for quick “messing around”, which way do you turn the pot at the ECU to make it richer?

Thanks,

Rob