Yanmar 4BY High Pressure Fuel Pump

royf

Member
Joined
Aug 27, 2020
Messages
6
Fluid Motion Model
C-28
Vessel Name
Fin Fisk
My 2012 27' Tug started having some issues last summer with a bit longer to start and a check engine light when throttling up past 1600 rpm. No code was shown on the Yanmar display. Stopping the engine and restarting reset the alarm. So prior to winterization here in Wisc (on the Mississippi) I had both fuel filters changed.

This spring we put it in the water and it wouldn't start. The mechanics came out to the dock and checked over a bunch of stuff (they're mostly outboard and inboard gas guys) and brought it back to their shop on the trailer. Eventually they changed out the solenoid fuel valve as it 'wasn't clicking'. That didn't help.

A mechanic at another marina said he could get it fixed so we trailered it there and he's decided after hours of troubleshooting that it's the high pressure fuel pump. There's no one to rebuild or refurbish them and a new one come from Germany with an installed cost of (well) used car. The folks at Ranger Tugs offered suggestions but the mechanic said his troubleshooting confirmed pressure to the pump and nothing coming out. He's trying one more option with 12 v on the solenoid to keep it open in case it is actually still the problem.

The engine has about 350 hours, so pump failure seems remote. Has anyone else seen this and dealt with it? Are there locations in the US that can work on or sell pumps?

I used to own a 50 year old airplane so I'm familiar with parts availability issues.

Thanks in advance!
Roy
Pepin, WI
 
Can you hear the electric fuel pump running. If so is the fuel being delivered to the high pressure pump.
 
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If I was you look for a Yanmar dealer, plant equipment etc. They should be able to connect to the ECM and be able to see fuel pressures etc. It sounds fuel related.
 
Yes, there is significant pressure to the low pressure inlet of the high pressure pump and the codes on the ECM were read with the Yanmar interface cable in place. It does appear to be fuel related.
 
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