Over Memorial Day weekend I started the coach after sitting for the past few months, and it started instantly. Everything was great for about 15 minutes; I was testing the engine stop switch from the engine compartment and everything seemed to be working fine. Then… while idling, the engine just stopped. I tried to re-start and nothing, the started turned the engine but the engine would not start. Since the 2-cycle DD engine is so simple, it was either not getting air or not getting fuel.
My first action was to check the fuel filters. This was the most likely culprit since I did not change them since my trip from California where I burned through the 15 year old fuel in the tank and likely had a bunch of sludge I caught in the filters. I replaced and primed the filters and tried to start it again. It Started, I thought that was easy. About 2-3 minutes later the engine stopped again.
Hmmm… I wondered maybe I did something when messing with the engine stop switch and maybe the skinner valve was messed up. Perhaps there was a jammed-up injector or a frozen rack. I could move the throttle freely and when checking for air in the line between the skinner valve and the engine stop valve, it was clear. Maybe the rod stuck in the fuel off position….
I popped off the fuel filters again and they were dry. It looks like the engine ran with the fuel in the filters and then stopped. I verified this by filling them up and the same thing happened, ran for 2-3 minutes and then stopped. There was no fuel getting from the tank to the filters. Next, I popped off the one-way valve that sits between the primary filter and the line from the tank, it seems to perform correct, I could blow air in one direction through it.
Next, I thought there must be something blocking or a break in the line to the tank and I figured I could back-flush the line with diesel and either reveal a leak or clear the blockage. Off to the hardware store where I picked up a ½ gallon garden sprayer. I filled the garden sprayer with diesel and proceeded to pump it up and attach to the fuel line to the sprayer. It did not clear, It only pressurized the line with fuel and when I removed the sprayer nozzle it all came back at me. Now I knew I had a blockage; I came back with a tank of compressed air and while disconnecting the line from the tank I blew air though until it shot out the other end. The fuel was thick, cloudy, and full of gritty particles likely rust.
Now I was sure I solved the problem. I put it all back together. Primed the filters and the engine started right up. In 2-3 minutes, it died again.
Now what…. Is the filler tube broken inside the tank? Like sucking through a straw with a hole in it? Is there a leak somewhere that sucks air but does not leak diesel? Did more gunk clog up the line from the tank to the primary filter within the first few seconds of running?
Saga continues…….
