ECU MAF!!!!

88-89 ecus will require that you return the maf circuit to its original configuration. The maf modification changes the offset voltage between what the afm puts out and what the ecu reads. IF you don't return the circuit to stock the input voltage from the z31 maf going to the ecu will be too high and throw everything off. It's likely the same for the other year ecus as well. Basically you have to put it back to stock. If you're planning on swapping a lot you can wire in a switch so the maf circuit mod can be done/undone just by changing the switch.