Hi all! First post here. I'm baffled. I have a fair amount of diesel experience, but I'm no diesel mechanic. I have an older case 480 LL. It starts right up. Runs for about a minute at idle, not so long at full throttle, then dies. If I let it sit a minute or so, it starts right back up, then dies again in a minute or so. I suspected fuel filters, and replaced them both. Problem still exists. Air filter dirty, but I've seen worse. Tried running it without the filter, same result. Engine has oil, and water. Battery is good. This appears to be gravity fed, and the return goes straight to the bottom of the tank. I anxiously await your thoughts.
Two possibilities, either it's starving for fuel because the fuel supply is blocked, or this could be one of those injection pumps that stops when the outlet gets blocked. You could try taking the line off the tank, make sure it's clear to the first filter, and run it on a temporary tank, even a can of fuel. Does your fuel tank have a petcock drain on it? See if the fuel comes out of there clean or if there's junk. Drain the tank if you have to and rinse it clean, look up the "suckbucket" if you need to vacuum the bottom of the tank. If it doesn't seem to pull any suction when it dies (if there's a rubber hose it should feel different as it dies, and as the suction drops after it dies) the other thing is the return, take the ENTIRE fuel return fitting off the injection pump and see if there's junk in it. Cleaning the junk is a temporary diagnostic thing only, most likely the flex ring is coming apart (got that right PG?).
OMG. Just had a call with a service guy. Would you believe fuel cap? Loosened cap. Runs fine.
Y'all beat me to it. I'd assume fuel cap means a venting issue. Can't say I've seen one get that bad that quick.
Tank must be full?
I don't believe it.. lol