Help! Fuel Pressure way to high

I have broken two filter caps. My fuel pressure is well above 100. My FPR is shimmed, has been for a year. This high pressure is new. I took the shim out, and in fact took out the spring and plunger. IT was empty and just put the cap back on to check. Still the same well over 100psi. I then blew some air into the return line to see if it was clogged. I can hear it bubbling in the tank. I ran a hose from the return port into a bucket and psi is still well over 100 and it just barely flowing into the bucket.
My FPR screen has something(light colored gunk) on the inside of it. Not the normal dark gunk on the outside. I took out the whole screen unit (small plastic piece with two orings with the screen attached to the end) to see if I could get behind the screen. I dont think I can without breaking it. Could this be causing the High Pressure?

I took the whole housing off and cleaned out the inside very well. I took everything apart that I could and cleaned. The only restrictions that I seem to find are in the FPR screen and the plastic housing that it is attached to.
Any thoughts??

scrawny said:

I took the whole housing off and cleaned out the inside very well. I took everything apart that I could and cleaned. The only restrictions that I seem to find are in the FPR screen and the plastic housing that it is attached to.
Any thoughts??

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Clogged Injectors ???? What is after the fuel pump????

What did you shim the regulator with? I am thinking the regulator might be bad or may have been damaged internally by over shimming.

The only other thing I that comes to mind is a old TSB (technical service bulletin) that warned about the fuel tank selector valve not switching over completely and not allowing fuel to properly return to the tank. You say you checked the fuel flow back to the tank so it is probably not the problem but a half switched tank valve would allow some return fuel flow but not enough.

I shimmed it with the BB. I did this a year ago and had consistently been running about 75psi. I took out the spring and the "plunger" that the bb goes in and put the brass plug back in just to check and the psi is still way over 100. So it is not the actual regulator spring that is holding up the psi.

The resistance is definetely in the FPR. I ran the return line into a bucket to eliminate the possibility of tank or pollack valve.

There is a filter (screen) on the bottom of the FPR (not the screen that people clean that goes into the side of the fuel bowl) That is more of a filter than a screen. I am wondering if that could be clogged. I have never heard of anyone replacing it. I checked with Ford and that part is available to order, I just don't know if that is it and dont' want to order it if it isn't ($70).

Hopefully I can figure it out over the weekend. Any thought and or suggestions are greatly appreciated.
Thanks
Donny

As it turns out, it was the filter at the bottom of the FPR. It is a wire mesh filter (cylinder about an inch long and as big around as a dime). It was very dirty and restricting the flow enough to build pressure. I replaced it and now pressure is back down around 75.

Thanks for posting the fix.

Russ said:

Thanks for posting the fix.

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ditto!

The FPR filter would explain the high pressure on the high pressure side, but not the broken filter cap which is on the low pressure (lift) side. I'm still curious what the issue was there. Maybe there was a surge of fuel back through the filter faster than the return orifice could handle?