Air in fuel system

He change fuel filters, checked fuel lines and the cap on the tank to make sure it was venting properly. However the problem persisted. Finally he decided to drain all the fuel out of the tank and check inside.

What he found was the silver round tab off a plastic oil bottle had found its way into the tank and after a couple of hours of operation would suck to the bottom of the tank outlet and restrict the fuel. He used a pair of long wooden dowels to fish it out. Problem solved.

So often something simple cause what we may think is a complex problem.

Good luck

Install a clear line, Tygon tubing works well, in the return line, then squirt a heavy oil, like motor oil, around each fitting while abserving the clear line for bubbles in the fuel. When the bubbles stop flowing, you found your suction leak as the oil will temporary plug the leak.

A suction leak can leak air but not fuel.

T_Bone