LSJeepTJ

I have '97 Jeep TJ that I have put a 5.3L in out of a 2005 GMC Sierra. It's the L33 aluminum block. It also has the 4L60E behind it. I had Novak do all the wiring as well as wire into the Jeep PCM so all my gauges work. I'm in Alaska so they did the wiring and I installed it all. Anyways the Jeep has no exhaust on it just the sanderson block huggers. Well it starts and runs and all the gauges work but, the driver side header dumps raw fuel out of it. So bad I can't let it idle. So I started unplugging injectors and found that the #5 injector when it was unplugged the fuel dumping out stopped. So of course I pulled the rail and bought a new injector and replaced it..well it still does it?!?!? Any ideas, thoughts or comments would be greatly appreciated.

i r teh noobz

iTrader: (4)

I'd look at the ignition or the wiring. Could be a shorted injector harness or a dead #5 coil.

LSJeepTJ

Sounds like a good idea. It's definately a direction I wouldn't have otherwise checked. Appreciate the reply. Thanks

LSJeepTJ

I tried swapping coils around and that didn't make a difference. I think like you say #5 plug in has a short in it somewhere. When it's plugged in and you hook the battery up it arcs towards the post. When you unplug #5 and then hook the hot lead up on the battery it does nothing...wonder what could be happening? It's a scary thought but, the only way to find it is to trace back injector wires? Yikes.....

Docked Wage

Keep in mind that when the key is on the injectors will get a constant positive signal (pink wire) and the PCM switches to ground to fire the injector.

So what this means is you need to chase the (-) side of that injector wire back to the PCM. If the injector is staying open you'll find that wire is grounded along the way somehow.

LSJeepTJ

Thanks for the info. Definately helps me out in chasing this down.

LSJeepTJ

So I did find the - side of the injector coil and cut it before it plugs into the computer and also cut it before it plugs into the injector eliminating the wire from the harness. Then I ran a wire outside of the harness straight from the computer to the injector and its still doing it? Odd thing is the injector when plugged in from the - side shows 12 volts? Is that normal? The other ones are showing 0.00 And as soon as I touch the wire from the computer to the injector it sprays....Also if you let it sit there with the key on it periodically sprays into the cylinder. Is it an ECM problem?

Docked Wage

Bypass the other wire (the pink one) from the injector and run it straight to a 12V (+ Key on and cranking) source.

Note that all of the pink wires going to the injectors should be 12 V (+) when the key is on or in the crank position. The ECM provides the ground path and causes the injector to open.

If there is still a problem even with both sides (+ and -) of that injector bypassed from the harness, I'd say there's an issue with the ECM.

Docked Wage

What did you end up finding out?????

99VetteFRC

Put a test light on the - side of the injector connector and the clip side to the battery + and start it and see if the test light blinks. Or you can put a noid light on the connector and start it and see if it blinks. If either stays lit all the time and you say you have run an overlay wire then there is a PCM problem.