Diesel bug!

[Dry Rot]

My MF 390 just stopped. Quite abruptly. Bled the system and off we go again. Then, stop! Again. I cleaned the lift pump which was full of gunk, then onwards with more problems which I will not bore you with. Couldn't resurrect the lift pump, so replaced it along with a new fuel filter. I have syphoned off a lot of fuel with gunk in it and fuel is finally reaching the (replacement) lift pump although intermittently which I assume is again choking. Checking that again is today's project. Is the only solution to take the tank off? And when I've done that, how do I make sure the bug doesn't come back again? There really was a lot of debris in it for which I blame the previous owner. The tractor with a four rotor tedder on the back is currently sitting in the hay field and not ideally located for repairs. Thank goodness for the quad as it saves walking whenever I need a different spanner.

 

[Zippy768]

My MF 390 just stopped. Quite abruptly. Bled the system and off we go again. Then, stop! Again. I cleaned the lift pump which was full of gunk, then onwards with more problems which I will not bore you with. Couldn't resurrect the lift pump, so replaced it along with a new fuel filter. I have syphoned off a lot of fuel with gunk in it and fuel is finally reaching the (replacement) lift pump although intermittently which I assume is again choking. Checking that again is today's project. Is the only solution to take the tank off? And when I've done that, how do I make sure the bug doesn't come back again? There really was a lot of debris in it for which I blame the previous owner. The tractor with a four rotor tedder on the back is currently sitting in the hay field and not ideally located for repairs. Thank goodness for the quad as it saves walking whenever I need a different spanner.

Drain the tank best you can and start with fresh clean diesel and add an biocide fuel additive.
Have it in combine. Been managing it for the last few years. But then forgot to put additive in before winter 2020 and problems started again

 

[milkloss]

On our old tractor we take the bung out of the tank and pump the diesel round to rinse the lumps out. Dose of marine 16 sorts the rest.

 

[milkloss]

Don’t waste the old diesel…… just filter it and make sure it’s treated.

 

[Pistonbroke]

We've just had similar with a case 5120 and it's been misfiring at low revs. Every place I've spoke to said to have the injector pump reconditioned but local car spares place said to try this stuff
If you read the label it doesn't sound like the right stuff but it's cured the tractor,cured a strange fuelling problem on son's Corsa and also just cured a dodgy running strimmer. Miracle juice

 

[Dry Rot]

Thanks everyone. I've got one of those tools for syphoning fuel, long plastic tube with a valve on the end. You joggle it up and down and it syphons the fuel out. Should have most of the lumps out. I read the blurb on one of these fuel cleaners and it did give the impression that it reduces the amount of sludge, so we'll see. Can't really face tank removal!