4 cyl Yanmar

I can’t get any fuel through to the HP side of the injection pump on my Yanmar 4JH3E. Although it has low running hours the engine has sat idle for at least 5 years. I’ve cleaned the tank of diesel bug, replaced all the filters, and am able to circulate clean fuel through the LP side of the injector pump and back to the tank via the excess fuel line. I just can’t bleed fuel as far as the HP pipes to the injectors. I’ve fitted an electric pump in the circuit so the system is pressurised. There is definitely no air being sucked in.
Stop solenoid works fine and the stop lever returns to the run position.
Cranking the engine over with injector pipes slackened doesn’t help either, still no fuel to the injectors.

Any advice?

PS. I’ve posted a similar cry for help in a boating forum without success.

Our boat (not yanmar) had fuel bug with previous owner, he had to have the pump replaced as an internal bracket broke and was NLA.
Is the stop solenoid just clicking or have you confirmed its working?
I could be wrong here but think the solenoid had/has two voltages. one to initially pull it in then another voltage supply to hold it there, that could have been the idle/fast run solenoid, its been a few years!

Close. Stop solenoid has two coils. One drawing a lot of amps to pull it in, and a lesser one to hold it in. Mine was working until this morning. I think I’ve burnt it out.

have you got this running yet

Rank Amatuer said:

Close. Stop solenoid has two coils. One drawing a lot of amps to pull it in, and a lesser one to hold it in. Mine was working until this morning. I think I’ve burnt it out.

Click to expand...

Feckin hell I was right!
I cant remember the UK suppliers of the yanmar engines 9barrats/barrens?) but we used them a lot years ago as we had loads of their engines, unhelpful bar stewards.
Engines were small and efficient and to fussy for my liking, lots of plastic bits as well, can remember even the lift pump had plastic poppets inside the casing, they liked to overheat as well.