Workin on an 89 F150, 5.0 I believe.

I finally got it running but it's starving for fuel. So much so that when I push down the little pin on the schraeder valve with my knife it kills the motor, and there is VERY little fuel pressure.

Now here's the kicker: I replaced the regulator and fuel filter.
Also, there is way more pressure at the filter, if I pull off the line I get sprayed with gas.

So I'm wondering if it's possible that I have a clogged line or something of that nature. Anyone ever heard of something like this happening?

 

What is your fuel pressure at the fuel rail?

If you pull the vacuum line off the regulator, does the engine idle increase?

If it's a clogged line, you should be able to pull the line loose from the regulator and the filter and blow out the line in-between those with compressed air.

 

Possibly one of the pumps might be bad, did you try to run the engine on both tanks? Does your truck have a hi\press pump on the frame? If it does try and listen to see if its working.

 

Yes I've tried both pumps, I can hear the frame pump working, and like I said there was plenty of pressure at the filter but barely anything at the rail.
Guess I'm just going to have to monkey around some more and see what I can do

 

Try this, remove regulator put finger over inlet port have someone turn key on then off just enough to run the pumps, you can at least see if there is any pressure coming to the regulator. Might sound crude but might be something and be careful of spraying gas.

 

It's been a while since I messed with the fuel system so help me jog my memory. I thought the high pressure pump pressurized the rail and then the pressure regulator bled off any excess pressure (if any) and returned it to the tank(s).

Try putting the return line in a container. If you don't have pressure in the rail but gas is moving through the regulator you will see it come out the return line.

Check to make sure you put the fuel filter in the right way. Don't laugh, I have done lots of stupid thing like that.

Check the lines for kinks something might have gotten bent and is cutting off the fuel.

 

Correct, but that will see if the pumps are working, the low pressure tank pumps will push through the rail pump still giving fuel flow, even if the hi pressure pump is bad it will still give some fuel flow, if the injectors are clogged you should still have pressure at the schrader valve, you might even pull off the return and finger it and see if it builds up pressure, this might also tell if the hi pressure pump is bad or there is a restriction somewhere. The filter is before the frame pump, maybe a bad frame pump might be the restriction. As I said because the pump is working, the vanes might be bad or the bypass might be stuck open, not building pressure, the in tank pumps are basically low pressure booster pumps, that could be the pressure you are seeing at the filter and the little you see at the rail.