5.0 not getting fuel.....
 

I have an 1988 f250 5.0 MT, that will crank over but is not getting fuel. The fuel pump (high pressure one, there is three on the darn truck) is reading 12v with the key on. However, when I crank the engine there is 0psi at the fuel rail. If I put 12v's on the high pressure pump it whirrs and puts up about 42psi. But if I do that and try to start the engine nothing....

I've also put a cheap OBD I scanner on it, (the $20.00 one from autozone that blinks codes out) it wont read any codes at all. It just leaves the little light on no matter what ?

And the engine does start up on starter fluid and then die out.

If someone cant give me some help I'm just gonna start the thing on fire soon.

Thanks in advance !


HELP !

wait so the pump 12v with key on? but if you supply 12v(with a jumper wire or power probe im assuming) the pump starts to pump and read psi? that doesnt make sense at all

Your telling me!

The fuel pump relay is good (I replaced it already). It has 3 pumps because it has two tanks on it. So two low pressure pumps and 1 high pressure pump. Which we know works because if I jump 12v's to it, it runs over 40 psi. The ground for the computer is good. And I've tried two different EEC's in it. (2nd from a junkyard).

For the fuel injector pulse the one is a red wire which is always hot (if I remember correctly) and the other wire grounds it?

The other wire goes directly to the EEC. So if I'm not getting a pulse its a bad EEC? (which means both of mine would be bad)

im not sure what tools you have access to but if you can find a "noid light" that would be the best way to test your injector pulse, or if u you have access to a wiring diagram and some sort of "lab scope"

To answer your question from the other thread, to find out which wire is hot check it with a test light.

I know how to find out which wire is out. I need to know which is supposed to be. I checked them and with the key on they're both running power through them? I have just about any tool you can use to work on a car.

I have a wiring diagram and according to it the red wire is a key on hot, and all the other wires run in the EEC. (which I've tried two of) So I'm guess the EEC wires should be the one's ground out?

if you had a noid light for the old fords it would just plug into your injector harness and blink every time the injector gets signal to fire. the other way would be to check for the power on key on, then you will need to figure out which wire has ground the other should be like a 5v reference or something without looking at a diagram its hard to say. and you can test for ground same way you check power (you might already know) using your lest light hook the gator clip to a 12v power source and then touch ground to complete circuit, light will come on with a good ground contacted.

pull the line apart at the fuel filter and see if you can make it pee. Jumper wire the pump. Trace everything from the back to the front.

if hes reading fuel pressure at the intake manifold then he will have fuel pressure at the fuel filter

p.s. have you checked for spark while cranking i forgot to even ask, if you have fuel pressure it might be easier to check spark and eliminate that from the equation.

You have 12v with key on but does it stay 12v when you try cranking without using the jumper wire?
You may have said it but I didn't catch it.