Yanmar 4JH80 starting issue

[Rustler20]

New engine installed by Yanmar agent in Largs, Scotland September 2020. Engine has performed well up to last Tuesday, when we were 3 miles off Dartmouth Harbour sailing and as the wind died went to start the engine but would not start, turned over but would not start. In the end we called a Pan Pan as needed to get safely back to our marina in Dartmouth. We had the local marine engineer come to the boat on Wednesday but he could not find the fault, what we did find was the voltage to the fuel pump solenoid was only 9V, so the assumption is it needs to be a minimum 11.5V for the solenoid to open?

Engine has only done 345 hrs.

He took the solenoid out and tested it externally with 12V and functioned correctly.

Starter battery delivering 12.5V, so all good there.

ECU output only 9V to the fuel pump solenoid, so could the ECU be at fault?

Fuel is clean but we could not find a lift pump or a prime to push the fuel through?
Any assistance appreciated.

[skipperpete]

For some reason Yanmar seems to have discontinued the manual priming pump that was on the earlier common rail JH series so you really need that electric supply pump to work. Its possible that you have a fuel blockage or a suction leak between the tank and your engine filter or that the supply pump has failed.
Before you continue dead cranking the engine it’s wise to close the raw water intake to avoid filling the exhaust. Do you have the engine handbook with the 4 pages of error codes and disabling actions? if not I’ll post them here.

[Rustler20]

Thank you for responding, If you could post the 4 pages of error codes and disabling actions from the engine handbook that would be appreciated.

[skipperpete]

Here are the codes and engine responses. [ATTACH]262984[ATTACH]262986[ATTACH]262987[ATTACH]262985

[Rustler20]

After further investigation the fuel pump has failed, signs of varnish/resin in the pump. Pump will have defective part replaced and then tested before putting back on engine. As a precaution, injectors and common rail being cleaned.
Hopefully the pump repair will be accepted under warranty.

[skipperpete]

Which fuel pump , HP or the low pressure feed pump? If you’re cleaning injectors and common rails it sounds ominously like the HP pump. Did the fuel come from the UK or Europe.
You should have had several error codes pop up on the screen for either of the pumps.

[Rustler20]

HP pump failure, no error codes came up!

[skipperpete]

Originally Posted by Rustler20

After further investigation the fuel pump has failed, signs of varnish/resin in the pump. Pump will have defective part replaced and then tested before putting back on engine. As a precaution, injectors and common rail being cleaned.

Hopefully the pump repair will be accepted under warranty.

I doubt very much that the warranty will be valid for a failure caused by contaminated fuel, good luck with it though.

[Rustler20]

Latest update -I recently suffered an engine failure that is likely to be ashphaltene contamination in my fuel, I understand this is not a diesel bug issue nor is it contamination of the fuel from dirt. It is in fact a product created within the engine due to high temperature and pressure combined.
I understand the standard size for ashphaltene is 2-microns. However, filters recommended for my engine system are 10 µm and there is a Racor filter system ahead of the engine which are 10-microns.
The question is, are the new generation Common Rail high pressure engines, whilst no doubt more efficient and environmentally friendly as reliable as their predecessors?
I also understand that taking diesel through a 2-micron filter is quite difficult and may not be as straightforward.