94 1500 no power to injectors

[chevy05]

I am working on a 94 chevy 1500 5.7 tbi truck I used my little light bulb on the injector wires and no power going to the injectors. I have only found about 10 fuses under thedash and all look good their. It will crank over great and the fuel pump is running when you turn the key on but will not start. So that is when I checked the wires at the top of the injectors and neither one has power. Were to start.

[Airjer_]

There should be a 10 amp fuse in the fuse block labeled INJ. Do you have power there with the key on. If you don't check for power at the coil. If you have power there than the problem is in between the splice of the pink wire that comes from the ignition switch and the fuse block.

If you have power at the fuse than you have an issue with the wiring from the fuse block to the injectors. The red wire from the fuse block splices to one red wire and one white wire. Those two wires are the ones that end up at the injectors.

[chevy05]

I am getting ready to go out and check a couple of them things and do you know that on this one if the module in the distributer has anything to do with the injectors having power. I was going to pull and run down and test it.

Okay I just tested I have power at the fuse and I also have power at the coil. That is far as I have checked. I am not sure which wire from the fuse block goes to the injectors I will have to dig around somemore.

[j cAT]

Originally Posted by chevy05

I am getting ready to go out and check a couple of them things and do you know that on this one if the module in the distributer has anything to do with the injectors having power. I was going to pull and run down and test it.

Okay I just tested I have power at the fuse and I also have power at the coil. That is far as I have checked. I am not sure which wire from the fuse block goes to the injectors I will have to dig around somemore.

I do not recommend LIGHT testers on troubleshooting engine computer issues ...

the use of a voltmeter is what is used/required to do this properly...

with the ignition on , the 12volts is applied to ALL injectors, the computer grounds out the return side of injector for a period of time to adjust for correct fuel injection..

make sure the injector ground[s] are secure..

[Airjer_]

I guess I should have asked how exaclty you are checking for power at the injectors. Do you have a wire to the positive side of the injector and then another wire going to a good ground?

or are you checking for power by hooking wires up to the positive and negative side of the injectors?

The first way is fine. The second way is a no no!

The module has nothing to do with power to the injectors. The power comes from the battery through a fuse link to the ignition switch and then to the fuse block where it goes through the ten amp fuse and then to the injectors.

[chevy05]

To test power to the injectors I have a little light bulb device that you unplug the inector and plug the light bulb into the harness and it is supposed to light up. When I had the module out and tested it tested good but was still worried that it was the problem. I have read that it does play apart in the power to the injectors. So I have a 87 gmc that had the same module on it I pulled it and tryed it started right up and ran fine. So I bought another module and it ran fine all day yesterday.
Thanks for all the help

[Airjer_]

Now we get it. You had a noid light. You where not checking for power at the injectors you where checking for injector pulse. Two very different things. You likely had power to the injectors but the injectors where not being grounded by the PCM. I would bet that you didn't check for spark either? Very common for the module to cause this problem. Had I known you had no injector pulse I could have skipped the whole power supply explanation and gone right to checking for spark and checking the module.

[chevy05]

Sorry could not think of the name of the tester I was using. I also did check for spark and it had spark.