ford lehman 80 bleeding fuel system

[jpmccros]

Fuel Set up:

Fuel tank => racon glass bottom fuel filter => (down to) electric pump = > (Down to) lift pump (lowest point) => (up to) polishing filter => fuel injectors

Event:

So I was running my 80hp Ford Lehman for about 45 mins on idle and suddenly it shut off. My immediate suspicion was that it ran out of fuel. I checked below the racon fuel filter and saw clean fuel with no signs of air.

Then I looked at the polishing filter and found that it was empty. So my thoughts were that my fuel filter might have been bad. It didn't "look" bad, but I don't know what a bad one looks like, and I replaced it anyways and tightened the cap up.

Next I tried to bleed the system. I turned the electric priming pump on and went to see if the polishing filter was filling up...it wasn't. Then I opened up the two bleed screws on the injector block. There was some fuel exiting out of the farthest bleed screw, but nothing out of the nearest screw. I then used the lift pump priming lever (which was seized in place, until I worked it free), and started seeing some bubbly fuel going into the polishing filter. I kept trying to prime with the lift pump but didn't get any fuel into the polishing filter.

Why can I not get fuel into the polishing filter with the lift pump?
Shouldn't the electric priming pump be able to do this without me using the lift pump?

[brutb]

Possible bad fuel line to polishing filter......???

[jpmccros]

the line appears acceptable. The first time I tried to prime with the lift pump, bubbles were pushed into the polishing filter. This lets me know there isn't any blockage. I don't feel as though there is air entering this line.

If fuel is in the bottom of the racon sight glass, shouldn't the lift pump primer be able to push fuel into the polishing filter?

Do I need to open the racon filter to atmosphere to eliminate a vacuum effect?

[shakey doug]

Have you cleaned the filter screen in the top of the lift pump??

[jpmccros]

Originally Posted by shakey doug

Have you cleaned the filter screen in the top of the lift pump??

I wasn't aware that there was one (new to diesels).

[shakey doug]

Just undo the centre set screw and lift the cap off it may require a bit of persuasion to get loose due to old sealant and paint. Inside you will find a nylon filter screen, if this has not been cleaned for years you may have to remove the pump unit for a good washout as grit can lodge under in/out valves causing flow problems.

[jpmccros]

Originally Posted by shakey doug

Just undo the centre set screw and lift the cap off it may require a bit of persuasion to get loose due to old sealant and paint. Inside you will find a nylon filter screen, if this has not been cleaned for years you may have to remove the pump unit for a good washout as grit can lodge under in/out valves causing flow problems.

Thanks, I will check that out. Could the valve/diaphragm be suck in place? I wouldn't think so cause I was able to get some air bubbles and the priming lever felt like it was doing ok.

I'll check this out when I feel like diving into a small engine compartment