Yanmar 4JH3 TE no start after it shut down.

[sy_gilana]

Trying to help a boat that was towed in.


He suspected something in his prop, hit reverse while doing 6 knots, engines stopped, cannot restart.


This engine has the Zexel injection pump.

I have checked the fuel system up to the delivery point on the injection pump. While trying to bleed it, noticed there is zero delivery at injectors, as if the stop lever is engaged.
Tested the Magnetic Valve (Stop) and it clicks when the stop button is pressed at the panel, and the cable to it delivered 12v when stop button is pressed. (Still suspect it could be physically stuck in stop position)

With the electric lift pump running, and engine cranking, and bubble free fuel supply, and all injector lines loose, there is no fuel coming out of the return line, or the injector pipes.

How to test that the injector pump is turning? Remove cover center to the injector out ports?

Any other ideas please.

[sy_gilana]

Ok so the next day.

I removed the cover in the center of the output ports and cranked the engine while holding a wooden dowel against the end of the plunger, it is moving in and out, so the mechanical part of the injection pump is working.

I filled the entire pump with clean fuel, and it appeared at the return port.

Cranked engine, and not one drop of fuel comes out of the HP ports.

Theory is that the engine suffered an overspeed condition and the governor went to an extreme position of reduce fuel, and is stuck there.

Does anybody know how to release a stuck governor after an overspeed condition?

[sy_gilana]

Next day...

I opened up various parts of the pump, there is rust on all internals. The pump needs to be replaced.

Does anyone know the MAIN Yanmar dealer in or near Miami?

[DougR]

The southeast US distributor for Yanmar is Mastry Engine Center in St. Petersburg, FL.

Or take the injection pump to a good injection shop in your area and let them have a look at it.

DougR

[sy_gilana]

Just to close the story. Ordered a new pump from Japan through a dealer in Miami.
Shipped to San Andres.
Replaced pump, started first time. Running like a dream.
$3442.00 for the pump.