Fuel Filter Mystery

[OlKoot]

Your system integrity is week. All, connections, and any rubber lines needs a good going over. I start at the return line, and go forward. Tank, lines ,no looseness. Rubber lines can get a flip, inside that plugs fuel, one way. Return lines have to be tight. Then, filters, feed lines, I'm using a 3/8th feed line, mechanical pump, and double up on clamps. A marine 2 micron filter. I'm also running a heat exchanger which heats my fuel up. Helps in Canada winters too. All this, before any kind of diagnosis, of the inj pump

 

[Black dawg]

Like mentioned a couple times, cut open a filter and see what is plugging them. Have seen several modified filler necks (between cap and tank) let stuff in.

 

[Duke57]

Like mentioned a couple times, cut open a filter and see what is plugging them. Have seen several modified filler necks (between cap and tank) let stuff in.

"Have seen several modified filler necks (between cap and tank) let stuff in" YES, check those.

Also check your fuel tank vent hose to see if it is clogged. Mine was packed with hard solidified dirt. I would think that a fuel cap has a one way vent or flapper that would keep a vacuum from developing in the tank even if the vent hose is clogged..

 

[Bart F-350]

"Have seen several modified filler necks (between cap and tank) let stuff in" YES, check those.

Also check your fuel tank vent hose to see if it is clogged. Mine was packed with hard solidified dirt. I would think that a fuel cap has a one way vent or flapper that would keep a vacuum from developing in the tank even if the vent hose is clogged..

No, still today you have certain caps that are ventilated, and certain that are not.

 

[Duke57]

Good point.

 

[rhkcommander]

Rubber hose can collapse internally, if the filter media is clean and the lift pump doesn't do it try replacing the rubber. All else fails, probably the IP going out and the air intrusion from a filter job is messing with timing. I haven't read the thread in a while, it's all a guessing game until you narrow it down. Good luck!