LSX FACTOR

I have a 02 5.3 engine in my 70 Chevelle. I used the factory harness and removed extras. Engine was running in car and then I spliced wires to move computer into car. #1 injector has power and stays open, filling cylinder with fuel and drips out of exhaust when turned over. When I put a test light on injector in series it lights up. When I push a wire into the computer that closes the circuit on the number one injector their is no signal. All other injectors test good at the CPU. I thought the CPU might be bad and sent it back to the programmer and sent additional CPU for programming. Programmer tested CPU on his car and it worked and sent me back two CPU that worked on his car. Please help. I need this car to work for basic transportation needs ASAP! Thanks for your help. This is my first time asking a question on a forum. Sorry in advance for lack of tech knowledge.

gMAG

iTrader: (1)

To make the inj 'fire', the cpu switches the ground to each cylinder (injector) in turn using the firing order. I'm wondering if somehow, you've either created a short between the battery lead & ground lead only on cyl #1, or the ground lead for inj #1is actually wired/shorted directly to ground, rather than to the cpu.
In order for the inj to remain operated, the grnd would have to be permanently operated through the injector.

02NavyBlueZ

you definetly have a short to ground on that injector wire. I would untape your harness and trace the wire from the injector connector back to the pcm and i bet you'll find the problem, chances are you probably connected it to a low reference wire @ the pcm instead of the injector 1 pin so i would check that cause you may also have a sensor that your sending ground pulses to due to them being crossed.

02NavyBlueZ

I just looked over a 02 5.3L PCM pinout and I noticed that the Injector #1 wire PIN 36 @ the PCM is BLACK, there is also 2 other black wires that are both sensor Grounds PIN 53 & PIN 54. Any chance you connected the injector wire to one of those pins instead? Disconnect the PCM and run a continuity test between the BLACK injector wire and the 3 PINS I listed above and see which one you get continuity on.

Pocket

iTrader: (22)

Grounding out another sensor's low ref wire would would set a low voltage code for that particular sensor

The injector problem sounds like one of two things. Wire pinch to ground or stuck injector. The latter is very common on engines that sit for extended periods of time. You can test the wiring with a meter or noid light

Wire pinch would always be grounded so test the pigtail to ground with the IGN off. Using the noid you unplug it and prob the two pins. Crank the engine up and watch for a blinking light

LSX FACTOR

Thank you for your response. I went out and removed the wire that went to pin #36 and removed it. Put a test light between it and the injector connector and the battery. There was no continuity. Traced wire and found out there were two black wires where I made the splice. I had reversed the two wires. Fixed the problem. Engine still doesn’t run, but one problem solved. Engine fires and runs for 10 seconds and then turns off. Last time It did this I put constant power on the fuel pump and it ran good. I must have other wires crossed up or something. Thanks again for your help.

02NavyBlueZ

No problem! Sounds like you may have a few others crossed too if its still not staying running. Let me know if you need the diagram for the 02 5.3 PCM

LSX FACTOR

Yes, Please send me the diagram for the 02 5.3 PCM if you have it handy. My e-mail is Christian@lsxfactor.com Thanks for your help.

02NavyBlueZ

Sorry for the delay man, I just logged on and saw this today. I sent you an email with 5 .pdf files attached. Let me know if theres anything else you need!