I've got a fuel pressure issue. It will run great for 10 - 15 minutes at 3200 or so then it just peters out. The fuel pressure falls completely off to 0. After is sits (get towed) for 10 - 15 minutes it will fire right back up and the fuel pressure will return to ~ 6 lbs. This is a mechanical fuel pump and a Q-Jet carb. It has a new water separator and all new rubber fuel lines. My gut feeling is there is sediment in the tank that gets suspended and after 10 minutes or so it manages to pack the sock on the tank pickup. Once the boat dies is sloshes around and the sediment falls off the pick up and it is fine again. Wash, Rinse, Repeat. It has done this pretty consistently on every long haul I have made with it. It does just fine if I stick to short runs
In conversation with another boater at the lake this weekend he said he had the exact same issue and it was the same style water separator. He said he bypassed it with just a regular inline fuel filter and it resolved his issue. He said he fought it for a long time before finally getting it resolved.
The tanks are tabbed in with glass and I don't think I can get the pickup out without removing the tank. The plan is to bypass the separator with a filter. If that does not fix it I am going to borrow a portable fuel cell from a friend and use that instead of the on board tank. If the borrowed tank fixes it I know I have an issue in my tank. If not it has to be the pump.
Anyone have any other suggestions? I'm all ears.