Dirty Diesel

[SVAmenita]

Hello,

3 months ago we bought a HR352, Yanmar 4JH3E. It had about half tank of diesel.
We serviced the engine after 5 hours after we bought it. Filters and oil were changed.
We used the engine for about 20 more hours. We were going to go out for some days so we got more diesel.
We probably used the engine for about 10 more hours. Then we added some additive (Datafuel from datacol). Couple of days later, turned on the engine, run for abour 10 minutes, started choking, and turned off.
Turned on, choked, turned off. Manually pumped some diesel and turned on again, and when increased revs turned off.
Obviously issue related with fuel supply.
Checked the primary filter, 5 times dirtier than the one that was removed on the service.
It seems I have at least the primary filter obstructed.
Also found diesel in the blidge. Primary filter is located right above the blidge, I didn't find any leakage in the filter but neither did I find anywhere else, I assume leakage came from it.
My theory is that there was dirty in the tank, adding more fuel first and additive either loosen or "fragmented" dirt getting in to the system.
Some questions looking for opinions/advice:
1- Is my theory possible?
2- I can imagine the most secure thing would be to empty tank, clean, change all filters, injectors, etc. Is there a sequence so I can test safely how to fix it without doing everything at once? Replacing primary filter, checking if it works, checking if it gets dirty fast again, etc? I don't want to be out of engine again so I need to be secure for the engine but also don't be caught unaware as long as I keep checking the filter.

Thanks!

[MikeHoncho]

Either clean/switch out the fuel or but a bunch of filters and don't add fuel until its almost empty and keep changing filters until they are clean. Not a great plan given you may loose power when you need it most. You don't mention the volume of fuel so either pump it all out and clean the tank or pay for fuel polishing.

[rognvald]

Mike,
I'd invest in a portable fuel pump and filter the old fuel into jerry cans, clean your tank completely, then re-filter fuel back into the tank and add some fresh fuel. Then, change your filters and bleed it at the engine mounted filter and injection pump. It should start without a problem unless it went to the injectors. Your initial mistake was trusting the original fuel without knowing the PO's maintenance regimen. Good luck! Rognvald

[PippaB]

The hope would be that the filter(s) did its job and no engine work is needed. Get a clean portable jug with clean diesel. Change the engine fuel filter. Run a temporary hose from the engine fuel filter direct to the clean fuel. Bypass your whole fuel system. Run the engine. If it is happy then you are left with cleaning your fuel tank, hoses, etc.

(You can leave the return fuel hose going to your tank as long as there is room in the tank, this would not be a long test.)