Re-wiring your fuel injectors to factory specs.

Parts and tools needed:

  • Wire strippers.
  • Electrical tape.
  • Heat-shrink tubing.
  • Soldering iron and 60/40 rosin core solder.

    The "Service Campaign" done by Nissan to all 84-89 300ZX's re-wires the fuel injectors to fire purely off the leads for only two of the injectors. It is speculated that Nissan did this to save on labor costs when the campaign was performed. What this effectively does is alter the firing order of the injectors so all 3 injectors per side fire at once (batch-fire mode). Now, there are really only two injector drivers in the ECU. The stock configuration is a batch-fire mode anyway, but wiring three injectors onto one lead both changes the firing order and shortens the overall wiring used. A harness ecactly like this one is used to connect 3 injectors to one lead:

    The remaining wiring is taped off and wrapped into the engine wiring harness. To rewire the injectors back to stock you will need to first disconnect the battery. Remove the electrical tape from the harness segments on either side of the intake plenum and locate the four additional leads that have been clipped and covered in heat-shrink:

    The tape is probably quite nasty as it gets after being exposed to heat. The best thing I have found to remove that adhesive goop is WD40 and an old rag:

    Clip the "Dealer installed" harness with enough free length to reach from each injector to the leads on the harness, be sure to leave some slack. Remove the heat-shrink from the leads on the harness, strip the insulation back and tin the wires with solder, then solder them together accordingly:

    SHrink the head shrink with a heat source of some kind and re-wrap the harness. Duplicate on the other side:

    Congrats, you're done.

    Go back.