Today I finally got done with modifying the GMPP engine harness. There were a few things that I did not like about it and I also wanted to give it some custom touches. The thought crossed my mind to completely reloom the harness, but I decided against it. Once I got the harness all hooked up and routed, it was pretty obvious that most of the harness is not really visible. It tucks very nicely behind the engine. The most visible parts are the extremities. The little branches that go to the various sensors, throttle body, and injectors. So I addressed just those areas. Here you can see how I kept the main branch of the portion of the harness that tuns along the fuel rail. What I did reloom were all the little fuel injector sections. You can also see the fuel line. It is a smooth bore Teflon braided stainless line that I covered with the nylon loom material.
Here you can see a section of the harness that had several branches going to the coolant temp sensor, alternator, crank sensor and MAF. It looked like this:
I changed it to this:
Not a huge difference, but a small detail.
I also routed the line from the coolant crossover tube. This tube can be routed to several places. The most popular is to run it to the radiator by the upper radiator hose. Others run a T in the upper radiator hose and routed there. On 5.3L Trailblazers the line runs to the large heater hose. So I drilled and tapped the water pump and ran a stainless hardline from the crossover tube to the water pump.
Getting really close to firing it up!
Andrew