4.3L Alpha One runs 6 minutes on topped-off fuel filter only

[greno]

If this boat sat for two years with ethanol fuel in it then the ethanol attracted water into the fuel and by now that water has separated out. The water will grow organisms that can plug the in tank screen causing a restriction. For old boats that have steel fuel tanks it can cause the tanks to rust and the rust flakes will float around and get drawn to the screen and plug it temporarily until you stop drawing fuel and they will again fall to the bottom of the tank. Next time the boat starts fine but after a few minutes running time the rust will start plugging the screen again. I never run ethanol in any boat after having fought a number of ethanol issues. And for storage I always use a diesel bio-guard along with Sta-Bil.

 

[den458]

My anti-siphon valve seems definitely stuck closed. I removed the hose connection from the fuel tank at the fuel filter. There was no fuel in that hose. I could neither suck fuel from it or blow air into it. If I can't suck fuel from the tank, I'm guessing the fuel pump can't either. That valve is seriously buried near impossibly under the floor. I cutaway some floor that extended over the fuel tank into the engine compartment & was just able to get a wrench on the valve, but it didn't turn free & I was afraid of damaging the plastic. I'm letting some penetrating oil work on it overnight, should get it off tomorrow, weather permitting. When off, I'll locate & install a new valve, check that I can suck fuel from that hose to establish the pump should be able to do the same. More tomorrow.

 

[den458]

Ultimately, it was the anti-siphon valve. Thursday, the valve seemed fused to the fitting it was screwed into, so I sprayed liberal amounts of penetrating oil & let it sit overnight. Friday, trying to wrench it loose, the anti-siphon valve actually broke.in 2 pieces. So Saturday I also had to replace the fitting that contains the fuel feed tube that reaches near the bottom of the fuel tank. Installed both new pieces using plumbers tape to make the threaded connections really well sealed. Then connected a new length of fuel hose with new hose clamps from the anti-siphon valve to the fuel filter. Keyed on the ignition & within 10 seconds cranking, the engine started & idled nicely. Ran it 20 minutes on a garden hose adapter, it was fine. Took it out Sunday on the Illinois River for the 1st time in 3-4 years, it was solid, we had a great time wakeboarding, kneeboarding, tubing. Thanks to all who contributed advice to aid my troubleshooting. All greatly appreciated. Hope I can one day share what I've learned to help others. Good day !

 

[tacx]

Glad you got it ironed out.