Yanmar diesel engine question

[Georgieboy]

I have a question regarding my 3 cyl Yanmar 3JH2E engine that I would like to throw out to anyone who may have some knowledge/experience with them. This engine had been sitting a long time. Once I start the motor it immediately revs to the max and stays there. The throttle lever control has no effect as does the engine stop pull control in the gangway entrance. The only way I can shut it down is to undo the injector fuel line to the injectors. I have checked the operation of the throttle and stop engine controls at the motor and they are operational. I have just taken off the governor from the fuel pump body and inspected. Everything looks good, not seized or rusted. I put it back together and still the same problem. I am at a loss here. Anyone ever have this problem before?
Thanks,

 

[kloudie1]

Sounds like the fuel injector volume control rack may be stuck in the wide open position. ??
The engine kill knob would not work because it does the same thing that the throttle does, which is to change the governor RPM set point..
When a governor controlled engine is shut down, the speed falls below the governor set and generally the governor may try to fully open the fuel injector rack.. so with the engine sitting there a long time with the rack fully open, it may have gummed in place and now refuses to go to the closed or minimal RPM position... ..
Only thing I can come up with..??
A good diesel mechanic could verify and pull the pump .. it may only need a squirt or two of something like carburetor cleaner to free the rack up..

 

[Steve Dion]

You can try a large towel on the air cleaner intake. The diesel will not run very long without air.

If you need a mechanic Bill Engle is located in the bay area and he should be able to fix you up. He has a mobile unit so he can come to your location. (510-708-9391)

He does most of the Yanmar work for everyone in our harbor up in the Delta but works out of the Bay Area. If you call him, tell him Steve from Hidden Harbor sent you his way.

 

[propellanttech]

Also check the diesel fuel. Make sure it isn't gasoline. I figure it's not, due to you already dealing with the fuel from the injectors. I figure this is your boat, that you have owned for a while, so an unlikely culprit.

I found this out with a diesel air compressor once. Some intelligent person put gasoline in it.

But the primary suspect is the fuel control is stuck in the wide open position. If this was a run away situation, the engine probably would have dropped a valve or slung a rod before you got it stopped.

James L

 

[Georgieboy]

Much thanks guys- this is what I was looking for. I actually did suspect the fuel control rack but I wanted other opinions. It does seem "stuck" as it is difficult to move. I have sprayed WD40 and tried to work it back and forth but it seems still quite stiff. I don't know if there is supposed to be a certain amount of drag on this slide bar but working it back and forth and spraying lub on it still does not free it up. I am afraid I am going to have to take the fuel injection pump right off? to get this resolved. If so, is the pump difficult to remove?
Thanks

 

[kloudie1]

The rack force specified for the pump on the 3 GMF is 60 grams.. which means it should slide of its own weight when the injection pump is out and stood on one end.. The pump on yours should be very "slidy" and not "dragy" at all..

 

[anchorclanker]

Re: stopping a diesel with a towel. Yes, it will work, but....

Diesels have no throttle, the air intake is wide open clear to the valves, and the engine is pulling an enormous volume of air, especially at wide open throttle. If the rag gets away, its going straight into the engine and will likely destroy it.

Cutting off the fuel is the safest way to stop the engine. Rather than a towel, a solid 3/4 or thicker piece of plywood over the air intake would also work.

 

[Endurance2010]

I agree with Steve D. Just call Bill Ingle and tell him the problem. He is the master of these engines and can figure out anything that is wrong with them. He doesn't charge for travel time in the East Bay and I think he lives in the Sacto area.