[pdecker]

Folks, this a follow-on to my earlier thread for my problem that I assumed was coil related. I installed a new coil, added a ballast resistor, and had the same problem of a hard shut down after 90 minutes and would not restart. I checked for spark and had plenty. I checked for fuel flow out of the fuel pump (disconnecting the fuel line into the carb) and had NONE. I jumpered out the OPSS, listened for the pump clicking which it did, and still had no fuel flow.

Yesterday, I installed a brand new MMI Facet electronic fuel pump, like the old one. Instead of running for 90 minutes, it now runs for only two minutes and shuts down hard. Plenty of spark, no fuel flow. Here's what I did to try to isolate the problem, and would like your advice to see what else I can do to fix it.

I disconnected the fuel line from the water separator to the fuel pump and stuck the suction end into my red dinghy fuel can. The outlet fuel line from the fuel pump runs to a coffee cup. I turned the key on, and the fuel pumped just fine from the fuel can to the coffee cup. I reconnected the pump to carb line. The engine started and ran just fine for several minutes with gas from the fuel can. So, I assume the fuel pump is working fine.

Next, removed the water separator/fuel filter element and inspected it. It is less than one year old and looked fine visually, and so I put it back.
I reconnected the line to the water separator and I removed the fuel line from the fuel tank and stuck it in the gas can. Once again, it pumped fuel into the coffee cup. I reconnected the line to the carb. The engine ran fine for several minutes until I turned it off. So, I conclude the water separator / fuel filter is fine.

Maybe it's the fuel tank vent. I was able to blow air fairly easily into the tank from the external fuel tank vent at the stern of the boat. It looked silly, but there is no apparent blockage. I removed the tank level sender through the big port on top of the tank, and confirmed there is more than half a tank of fairly fresh gas seasoned with a little MMO. I visually confirmed there was no gunk at the bottom of the tank and the screen as the fuel pickup looks clean. I reconnected everything, and it would run for only a couple minutes again and then stop suddenly. I removed the fuel tank cap to see it it is a venting issue and tried it again, and it would not start. Also, no fuel flow into the carb.

I'm thinking there must be something mostly blocking the fuel between the top fitting of the fuel tank and the fuel pickup at the bottom. How can I check, and how can I remove the blockage if there? The fuel tank is aluminum. A brass elbow is welded to the top connecting the fuel shut-off valve and the barbed fitting for the fuel hose. The water separator / filter is mounted slightly above the level of the fuel tank.

Phil Decker
S/V Catmandu
1982 Catalina 27