OE Z31 fuel system configurations by year.

I compiled this information in the hopes that someone might find it useful for ECU/injector/O2 sensor swap information. As these are the only major differences in the Z31's stock engine management, this should be what you need to figure out if a particular configuration will work for you. Granted, there are other small differences and this should not be taken as having been "set in stone".

·  All NA injectors are ~180cc/min and all Turbo injectors are ~260cc/min.

·  High impedance ECU on a low impedance injector will require dropping resistors to keep from frying the injector driver unit. You can order these from Digi-Key, Radio Shack, JWT, etc. I used 10W 7.5ohm wire-wound resistors from Digi-key, as I was already ordering some other stuff. The total for 6 resistors was $11.64 (without shipping), I believe JWT charges around $30. Most cars have probably had the injector service campaign done on them. If so, you will need to wire your injectors back to the factory configuration for the car to run. Instructions on how to do this will be written shortly, but for now JWT has the basic information in their 450HP upgrade installation manual.

·  Low impedance ECU on a high impedance injector should operate normally.

·  Feed type does not matter to the ECU as impedance and flow rating do, however the lower intake manifolds are different and will require shaving/shimming the injector mounting area for fitment.

·  Titania-type oxygen sensors are not compatible with zirconium type, and vise versa. Zirconium sensors relay a 0-1v signal and Titania sensors vary resistance to give the ECU its data. If you wanted to switch sensors to accommodate a 86-89T ECU, the wiring in the engine wiring harness would need to be changed, as well as the oxygen sensor bung (Titania are 17MM and Zirconium are 22MM).