GM Vortec P4

The wiring was the last thing we had to do. Most people think that the wiring is the hardest part of the conversion. So did I until I did one with the Fuel Injection Specialties modified loom. The loom is labeled and positioned to lay on the engine and connect to all the stock sensors. Once we had everything plugged in, we routed the main loom over to the driver side where we would mount the computer. We now hooked up the stock wires we removed with the engine and cut off the ones we didn't use. We still had to hook up the fan and fuel pump. The wire for the fuel pump is in the loom, it just needed to be extended to reach the fuel pump in the rear. When we wired in the fan we used a relay. This way we wouldn't overload the system. The rest of the wires we hooked up from the loom were the keyed power, check engine light, tach (if you have one), oil pressure (optional, we already had the stock one hooked up), water temperature (optional, we already had the stock one hooked up), and AC clutch (optional).

With everything hooked up and fluids in everything we were ready to make it run. We first bled the injector rail by turning on the pump and releasing the air from the pressure test fitting. This took about 4 or 5 times to bleed all of the air out. Once it was bled after a few cranks it started right up. After running it for awhile we were able run a scan on the system to be sure that all of the sensors were working properly. Everything checked out OK but we still needed to drive it for at least 60 miles to make sure everything was properly. Once the second running proved out OK it was ready to take to the smog referee and get a new smog sticker. This Jeep had to pass California smog regulations.

This technical article was written with the intent of helping you do this conversion yourself. If you find it a little difficult for you then we can do it for you. This conversion can be done at either shop. We have the facilities to do it at Pomona Gear and Axle Repair in Pomona, CA. or Hicks 4x4 in Williams, AZ. If you have any comments or suggestions about this article please feel free to contact us at either Pomonagear@verizon.net or Vince@Hicks4x4.com. Happy Conversions

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