Yanmar 4jh2-te won’t shut off

[Cpt Ron]

Hello, new to the forum.
Have a yanmar 4jh2-te that keeps running after pushing the stop button. Solenoid is working properly and will not shutdown even when manually pulled the engine rpm will drop to barely idling but just keep jugging along, had to cover the air intake to kill it. Any ideas, I don’t really want to replace the injector pump.

[skipperpete]

How did you manually pull the stop solenoid? Its a real test of agility getting to the stop lever between the injector pump and the engine block. I’ve seen a couple of these loosen off to the point where the solenoid runs out of travel before shutdown happens…. I actually preferred the older version with the cable stop.

[Cpt Ron]

My solenoid is mounted on a bracket separate from the injector pump with a 3in linkage arm and boot going into the pump, very easy to grab the linkage and pull it

[pcmm]

I had to replace my stop solenoid recently for the opposite reason, it was getting stuck closed, stopping me from being able to start the engine. Has anything changed recently? replaced solenoid? You can disconnect the stop lever from the solenoid actuator and operate it that way. Might be the solenoid can no longer actuate for the full required stroke. Mine was pretty corroded. the actuator which is a steel rod was pretty corroded . Depending on where the corrosion i, this might change the available travel of the solenoid.

In my case I replaced the solenoid, only to find out that the replacement part was not identical! the mounting ears were different, but not enough to make it not work.

[A la carte]

My Yanmar was doing the same thing, but wasn't the solenoid or button (which are likely candidates). I found some electrical connectors behind the button were not making great contact. I soldered and shrink-wrapped ... problem solved.

[skipperpete]

Originally Posted by Cpt Ron

My solenoid is mounted on a bracket separate from the injector pump with a 3in linkage arm and boot going into the pump, very easy to grab the linkage and pull it

The only way to accurately investigate the stop lever travel and consequent ability to shut down the engine is to undo the solenoid from the bracket and pull directly on the exposed plunger. Just pulling on the link in situ will bottom the plunger in the solenoid case and not allow full travel. If yours is the 2 stage solenoid its possible the pin that activates the hold in coil is stopping full travel.

[Cpt Ron]

Will pull it apart tomorrow, kind of a pain to get at.

[GordMay]

With a mechanical valve rack, to the fuel injector pump the fuel solenoid is ‘open’ [fuel flowing], with the piston extended, and ‘closed’ [engine shut down], with the piston retracted.


To shut down an engine, with a frozen [extended/open] solenoid, or a faulty stop circuit, temporarily jumper the +12V terminal, on the solenoid [red, or grey /w yellow stripe?], to it’s case ground.
The piston should retract; but if not, tap the solenoid, to free it.