Long DTC 360 Won't Stay Running

[nobbyv]

I have a 2004 Long Agribusiness 360DTC with the 39HP 4-cyl Mitsubishi diesel engine. I bought it about three years ago and it has run flawlessly the entire time I've had it.

Today while running it, the revs suddenly dropped, and it started sputtering. After about a minute of this, it died. I restarted it, it ran for about 10-15 seconds, sputtering the whole time, then died again. That is the current state: it will start, then sputters for a bit and dies. I was thinking that even though it showed ~1/3 tank, the fuel sender might be bad, so added 5G of fuel. No change. I did a tuneup about 5 use hours ago, including oil/filter, both air filters, fuel filter, and hydraulic fluid. Note that I DID have an issue with diesel algae (if you want to see how bad a diesel algae bloom can get in a matter of weeks, see below), but I shocked the fuel tank with biocide, ran it for a bit, dumped the tank, changed the fuel filter, filled with new fuel and added a maintenance dose of biocide, and since then the filter has looked good. Just in case, I swapped the fuel filter again today when it started running poorly, no change.

It sure seems like a fuel issue to me, as it cranks and starts. Is it possible some gunk snuck past the filter while dealing with the diesel algae and clogged the fuel pump or something? Any other advice on what to check?

 

[Roadworthy]

Remove the filter and put a bucket in its place. Turn on the fuel and check the flow. That will tell you whether there is some blockage in the tank preventing fuel from passing. You could have an old clump of algae blocking the fuel at the tank exit. You may have killed the algae but it's possible you still had a clump of dead algae in the tank.

 

[nobbyv]

Remove the filter and put a bucket in its place. Turn on the fuel and check the flow. That will tell you whether there is some blockage in the tank preventing fuel from passing. You could have an old clump of algae blocking the fuel at the tank exit. You may have killed the algae but it's possible you still had a clump of dead algae in the tank.

Good point. I'll try that today. However, the "cartridge" that holds the fuel filter is clear plastic, and it does look like diesel is getting through.

 

[nobbyv]

So I tried this today. Removed the fuel filter, left the filter canister off and turned the fuel shutoff back on. When I turn the ignition to "On", I get air pulsing at the fuel canister inlet, but no fuel flow. I can hear gurgling from the fuel tank. So it seems to me like the fuel pump is fine, but there's maybe a blockage at the fuel pickup in the tank. Which would make some sense if there's a bunch of dead diesel algae floating around in there. Agreed?

 

[Roadworthy]

I'll agree with your assessment - kind of. The tank probably exits at the bottom. Gravity would tend to pull solids down. Any draining action of the fuel would try to carry them out. Obviously they're not coming out. you may be able to pressurize the tank at the filler cap - say to five or ten pounds - and possibly force the solids through the line. If there's any kind of filter screen in the tank this won't work. If you can pump the fuel out of the tank you may be able to remove the output fitting. I don't know your tractor at all. I just know this could get real ugly real fast. Good luck!!!

 

[nobbyv]

I'll agree with your assessment - kind of. The tank probably exits at the bottom. Gravity would tend to pull solids down. Any draining action of the fuel would try to carry them out. Obviously they're not coming out. you may be able to pressurize the tank at the filler cap - say to five or ten pounds - and possibly force the solids through the line. If there's any kind of filter screen in the tank this won't work. If you can pump the fuel out of the tank you may be able to remove the output fitting. I don't know your tractor at all. I just know this could get real ugly real fast. Good luck!!!

Thanks for the input. I was able to figure it out (and it was what you suggested): someone put a shut off on the fuel hose just after where it leaves the tank. So I closed the shutoff, disconnected the hose after the shutoff, then opened it back up, and all that came out was a few drips. So I grabbed a (clean) fiberglass driveway marker and stuck it in the tank through the filler and swirled it around. After a few seconds, fuel started pouring out. So there clearly was something clogging the outlet. I'd say with almost 100% ceryainty dead algae. So it looks like I'm doing another tank flush. Thanks again!