BF225 How does the Internal Fuel/Water Separator Work?

Here is what I have done:

Drained & Cleaned VST
Replaced LP Fuel Pump - old one was a lot more difficult to push in vs the new one.
Replaced LP & HP Fuel Pump Filters and orings
Replaced Squeeze Bulb
Bypassed all external filters when I replaced the bulb and ran fuel direct from the tank through the bulb to motor.

I have fuel up to the Fuel/Water separator and can fill up the second internal filter with the pump bulb. Now here is the issue, sometimes the LP FP sucks all the gas out of the 2nd filter and the motor dies. Sometimes when I crank it up after, it wont start due to fuel starvation. Other times, I can see it dump fuel in the filter and it will run until it goes dry again. It's like there is a valve in the fuel/water separator that works at startup, but then closes after the motor runs for 10-15 min. BTW, I have dumped the Fuel/water separator many times and no water is in the bowl. I thought there is only a sensor that gets activated if water floats the bowl up, but it seems like there is a valve that is shutting off the fuel to the second filter. Also doesnt seem to be leaking air in the fuel line of oring on the fuel/water separator.

Only ideas left are problem with separator or collapsed fuel line from separator to 2nd filter. No visual issue with fuel line that I can see.

Thanks!

Byrdman

There is a fuel line cut off valve right near the low pressure fuel pump. Pull it and make sure it is working. My understanding is that it is activated upon rapid deceleration to prevent vapor lock in the LP fuel pump. Also, check the #5 10 amp fuse to make sure it is good.

Thanks Chawk! Fuse is fine. Already checked and HPFP whines upon key turn. I know the part you are thinking and I will check, but I think my problem is in front of the LP pump but if its not and cutting off fuel that could be it. seems weird separator full w/ no water and LP filter bowl runs empty.

Am i correct in the flow: bulb>on-motor separator>on-Motor filter>LPFP



I will check after work today and get back to you. I assume I can bypass it and see if she runs right temporarily.

OK. From your description it soulds like you have a fuel line restrictio9n somewhere in there.

There is no cut off or valve in either the on-board fuel/water separator or the LP fuel filter that I am aware of.

The first thing to check is the fuel line as it runs through that big black, round grommet as it enters the engine compartment. Several folks on this forum have reported that junk builds up in there and squeezes the fuel line. Also check right where the fuel line enters and exits that grommet for a pinched or collapsed fuel line.

Have you tried running the fuel line directly from the primer bulb to the LP fuel filter bypassing the grommet and the onboard fuel/water separator?