I think everythings grouded, i can check more closely in the light tomorrow. I can get a noid light. What will this tell me?
Will

 

That's generally indicative of a power problem to the computer, or a computer issue. However your fuel pumps cycling seems to indicate otherwise. I know some early EFI models didn't have a check engine light.

Anyways, so you definitely hear the fuels pumps running after a start attempt, right?

 

Yes, the fuel pumps definetly are running.

 

If the truck has sat for a long time you may have to clean all the injectors before it will run.
If it has not sat for a long time then either you have bad wiring to the fuel injectors or a bad computer.

Make sure the small black wire with a green stripe has a good ground connection at the NEG post of the battery.
The large NEG cable goes to the engine block and not the frame.
And make sure there is also a large (10ga) wire from the NEG post or engine block to the body.



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i used the noid light, I got no flashing at all. injectors are not working. is this a wiring issue? maybe a sensor?

 

You verified the injectors have 12 volts at them? If so, that means the computer is not even trying to fire the injectors.

I recommend purchasing an Innova 3145 code reader. They're about $25.

Just to verify about the pumps again:

When you first turn the key on, the fuel pumps only run for 1 second, then turn off, correct?

When you turn the key to "Start", then let go, you should hear the fuel pumps run for 1 second then turn off. Is this correct?

 

Yes both prongs on the injectors have 12 volts all the time. i will look into the code reader. With the pumps, that is exactly what happens.
Will

 

So as of right now, it looks like there is either:

A, there's open circuit between the injectors and the computer (the computer grounds the injectors to fire them), but it seems unlikely both would go open circuit (unless something ate the wires).

B, the computer is faulty

or C, There is a sensor issue. Generally there is only one sensor that can prevent the injectors from firing during start up, and that's the throttle position sensor. You can try unplugging it, and seeing if it will start.

Being able to check for codes will be a big help, however.

 

Where is the throttle position sensor located? I will try that tomorrow. If i dont have any luck with that i will get a code reader. Thanks for all your help. Cant wait to get this ole beast on the road!
Will

 

The throttle position sensor is located on the throttle body. It's on the opposite side where the throttle cable lever is.

 

If the injectors will not fire with the TPS unplugged then it is possible that you have an open wire #349 (a Dark Blue wire) between the Ignition module (PIP pin) and the computer pin #56.

This will allow spark and the pumps to run but the injectors will not fire.

 

Unplugged the TPS, the injectors did not fire. I will look for this blue wire.

 

The fact that his fuel pumps turn on while cranking indicates the PCM is recieving a PIP signal. Either that or the computer is being reset when he lets go of the key.

Do your diagrams state whether or not the 88 460 has a check engine light?

 

Yes the 88 had a check engine light, wire #658.






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I was not 100% convinced that the fuel pumps were running while the engine was being cranked or that someone had rewired the fuel pumps to run somehow.

The Dark Blue wire:




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