Yanmar 4JH3-HTE

[carlylelk]

We motored for 38 straight hours recently and after dropping anchor, when we pushed the "Stop" button the engine did not die immediately as in the past; instead it ran badly for 15 or 20 seconds (sounding as if it were running on one cylinder or on all four, but intermittently) and finally died.

The next morning it would not start. In the past this engine (2500 hours) would start instantly, no cranking necessary). I changed the fuel filter and there was plenty of flow on purging.

We were able to get it started by pumping (with the manual pump used to purge the fuel filter) with the throttle at half speed idle. When it started it ran very roughly for 15 or 20 seconds before finally running smoothly. We repeated that 3 times before it would start at idle. The next day it would again not start at idle, but would at half throttle repeating the prior day experience.

Prior to the 38 hour trip, I had changed the fuel filter so it could be air in the fuel injection pump, but how had everything gone well for 38 hours of motoring just before the failure?

I'm wondering if this is a problem with the "Stop" button solenoid in the fuel injection pump?

Any other ideas?

Duane

[a64pilot]

There should be I believe an externally mounted solenoid on the fuel injection pump, have the Wife push the button and you see what moves.
I'm betting it's sticking and your problem has nothing to do with fuel filters based on your description of the problem.
You should be able to move the lever yourself manually.
I am not familiar with your engine though it may have an internal stop mechanism, my 4JHE does not and I'm guessing about yours.

[Privilege]

I agree that it sounds more like a stop solenoid problem than a fuel problem. Reach down the side of your engine and find the stop solenoid. It's usually just a small lever with a concertina-type boot on it. When it is excited by 12v it pushes (or pulls) the lever and cuts off the fuel. Make sure that it hasn't stuck half way.

[Kenomac]

We have the same engine. Not sure from your description if this is related, but last season we had a nagging engine problem related to old cracked fuel lines that were sucking air. The engine would run fine when fed fuel directly from a jerry can, but not via the lines running from the fuel tank. We then changed out all the fuel lines and the engine ran fine.

A second problem then developed related to me having plumbed the fuel lines together for the generator and engine after the fuel polishing system. When the engine would run for an extended period of time, it would suck all the fuel leading back to the generator and begin sucking air. This very nagging issue (when Infinally figured it out) was then solved by the engine and generator having completely separate fuel filtering systems.

I think your engine might be sucking air from somewhere, check all your clamps and hoses. Just an idea. Are you getting any bubbles when you bleed the system from the final fine fuel filter? Good luck

The easiest way to confirm or eliminate this possibility is to run a new length of fuel hose from the fuel tank outflow directly to the fuel filter on the engine, and see if the issue continues.

[carlylelk]

A64 & Privilege,

I thought it might be the stop solenoid as well so I ordered one. It screws into the top of the Fuel Injection Pump (like a spark plug would) and the moving parts are inside the FIP, so I cannot manipulate the solenoid at all. I did disconnect the solenoid from power and then jumped it from the positive battery cable...I heard a distinct click so it sounds like it's operating, although you could be right and it's sticking partway.

It appears that I would have to dismount the FIP to remove the stop solenoid (the engine is above it and there is an adjustment screw in front of it) and since I've never done that I'm a bit leary. Aren't there engine timing issues with removing it?

[carlylelk]

Kenomac,

Thanks for the reply.

I'm also wondering if there is an air leak somewhere. It would have to be past the connection to the fuel injection pump because we loosened that fitting and when the engine is cranked it gushes fuel.

Next up I'm going to crack each of the injector connections and crank to see if fuel is getting to the injectors.

Thanks,
Duane

[carlylelk]

Any thoughts on how difficult a DIY job it is to dismount the Fuel Injector Pump?

I need to get a Yanmar Service Manual.

Duane

[a64pilot]

Yes, do not remove unless you have a handle on how to check timing.
Some say you can time by ear, maybe a real experienced person can, but if the timing is off it can cause engine damage so I would not do that.
I'd try actuating the stop button several times with the engine off and see if that clears things up, the click to me says the solenoid is working, and it cannot ever hurt to bleed the fuel to eliminate that as a possible problem.
I start troubleshooting with easy first, then cheapest before I spend bucks on a possible solution.
But from your description that just sounds like a stop solenoid, or one heck of a coincidence. It could of course be the valve in the pump that the solenoid actuates. You near a mechanic?

[jimbunyard]

How does the engine run if you energize the shutdown solenoid manually?

[Kenomac]

Originally Posted by carlylelk

Kenomac,

Thanks for the reply.

I'm also wondering if there is an air leak somewhere. It would have to be past the connection to the fuel injection pump because we loosened that fitting and when the engine is cranked it gushes fuel.

Next up I'm going to crack each of the injector connections and crank to see if fuel is getting to the injectors.

Thanks,
Duane

The air seemed to collect inside the furl filter just before it enters the engine on top where you can bleed the air with the little pump. Try bleeding your system with the little built-in hand pump on top of the fuel filter using the bleed fitting (the small bolt) in the picture. See if you get any bubbles.

Open the bolt a few turns and push on the top of the filter to pump it.

[carlylelk]

So, the engine has sat a few days now and this morning it started at idle just as nice as you please. http://www.cruisersforum.com/forums/...s/facepalm.gif

I don't think the story is over. I'm really wondering now if the Stop Solenoid is sticking sometimes and sometimes not. If it recurs then it's got to be the Solenoid....maybe...

Duane

[Captsteve53]

Duane, Removing the fuel stop solenoid does not effect the timing at all, a Novice could remove a fuel injector pump but replacement is another story as the engine will have to re timed and usually requires special tools/dial indicators and the likes, although the engine may run with out specialist timing damage to the engine internals such as pistons etc will probably occur sooner than later, fuel lift pumps can be replaced easily and does not have any connection with the injection timing,

[jimbunyard]

Don't know if your solenoid is energize to run or energize to stop, but at 300.00 for a new one from Yanmar, I'd be checking the wiring harness, the ignition switch and the stop button itself...hard to imagine it's a fuel problem after 38 hours of running. Intermittent symptoms often denote an electrical issue.