HELP w/ Ford Lehman 135's

[pogue-a-licious]

Greetings all! My wife Mary and I are baffled. We have a 49' RPH Defever w/ twin Ford Lehman 135s. Over the past three weeks, our starboard engine has randomly shutdown and the cause has been difficult to diagnose. We have consulted with two diesel mechanics and there is no real idea what might be causing the sudden rpm drop and subsequent shutdown.

We have replaced the fuel solenoid, and even disconnected the wire to the solenoid but the engine has still shut down on us more than once. There does not appear to be any water in the fuel. The engine is not running rough at idle or underway. In addition, there is no rhyme or reason as to when the engine quits. We can cruise several days without incident and then all of a sudden it quits. We have been able to immediately restart the engine, except once which was the most recent shutdown.


Recently, after cruising for three days without incident it shutdown three times within a 30-40 minute timeframe. After the third shutdown, I did bleed some air out of the starboard fuel line and the engine started. We decided to anchor for the night shortly thereafter and cruised 8 hours the next day without incident.

One mechanic, grasping at straws to come up with a theory, hypothesized that perhaps the Naiad stabilizer, which is attached to the starboard engine only could be requiring a large fuel input that the governor somehow cannot respond to. Could there be any merit to this theory? Any other insights?

Thanks so much for your help.

Tim and Mary Dent
mv Got the Fever

 

[Marin]

You might try calling Bob or Brian Smith at American Diesel. Bob Smith worked at Lehman and was involved in the marinization of the Dorset and Dover engines to create the FL120 and FL135. While troubleshooting over the phone is an iffy proposition, they may provide some additional things to check.

 

[BruceK]

A diesel needs fuel, air at the air intake, and compression, to run. Which of those is going missing? If you bled air from the engine fuel line and then it started, it points to air entering the fuel system. Was that event after the mechanic was racking his brain? If not, I assume he discounted it. If yes, maybe talk to him again, with the new information.

 

[FF]

IF it restarts after a pause my GUESS wild be a blockage in the fuel pickup in the tank.

This can cause no fuel or a very high suction that could allow air into the system .

A 6 gal metal OB tank fed directly to the fuel pump might help troubleshoot.

Or a glance at a suction gauge on your filter , AS it is shutting down

 

[Capt.Bill11]

Start by switching the fuel tank pick up points for the engines and see if the port engine starts misbehaving. If it doesn't and the Stbd still does then you know the problem is down stream of the tank.

Then I would check/ tighten every fuel line fitting, fuel filter fitting, injector line fitting and fuel filter gasket to make sure they are tight and that the gaskets are seated correctly. I would also consider changing out any soft fuel line to that engine in case the interior of the line is failing.

Consider switching fuel pumps between the engines to see what happens. Or just going ahead and replace the pump on the Stbd engine. They are not expensive.

If all this fails to correct the situation then start looking at the injector pump.

 

[Larry M]

... If you bled air from the engine fuel line and then it started, it points to air entering the fuel system...

I agree. It doesn't take much of an air leak, one that could very difficult to find, but that is where I would spend my time. Good luck.

 

[pogue-a-licious]

Thank you all!

Thank you all for your replies and forgive the delay in our response as we just returned from cruising for a week--this time without incident! We took your advice and searched for an air leak. We started at the beginning and discovered the issue lay in the improper seating of our recently changed Racor filters--we also called American Diesel--and again, as in the past, they too, were extremely helpful and generous with their time troubleshooting over the phone. What a great community!! Boaters helping boaters--Thank you again for taking your time to help us--our learning and knowledge continues to grow--very much appreciated! Happy cruising and until next time, be well. Tim and Mary, M/V "Got The Fever" All our best!