Installing resistors to run an 88-89 ECU with low-Impedance injectors.
This is by no means a perfect solution to adapting an ECU with injector drivers designed for high-impedance injectors (88-89) to run low-impedance injectors (84-87). However, it appears to work well for everyone nonetheless. By now you should have already figured out which ECU and injectors as well as oxygen sensor you are using as well as re-wired your injectors to factory specs.
Parts and tools needed:
- Wire strippers
- Six 10W 6-10ohm wirewound resistors (available from Digi-key, JWT, among others)
- Electrical tape
- Heat-shrink tubing
- Soldering iron and 60/40 rosin core solder
Disconnect the battery and remove the ECU from the passenger side kick-panel and remove the connectors. Pins 101-106 lead to the injector wires; you need to solder resistors in line on each one of these wires. The bottom connector (as the ECU sits in the car) contains pins 101-106 on the end of the connector opposite the locking tab. Notice the wires here, they are green in my harness (and most likely yours also).
Your resistors will probably look something like this:
Wrap some tape around the resistor itself and bend the leads around 180 degrees. Tin the leads and secure them to the resistor in the middle using a zip tie and/or electrical tape. I soldered little sections of wire onto mine to make the installation/removal process easier. Do it however you see fit, just make sure you don't have any chance of a short:
Locate the 12 prong plug at the ECCU and Clip the Green wires a couple inches from the connector, tin the wires (notice where mine were clipped and re-soldered):
Solder the resistors inline, heat shrink the ends and then wrap with electrical tape: