Engine went full RPM....now doesn't start

[andreas.mehlin]

The engine has been sitting for four years. It has been taken out of the boat and is now standing on a pallet.

Today I wanted to fire it up and see if it works. And, yes it does but it also went to full RPM without doing anything...tried to kill it manually on the injector pump leveler...Nothing happened so had to choke it on the air intake

Now it doesn't start at all. No fuel is getting to the injectors.

Suggestions? Sounds like something with the injector pump....what do u think and exactly what could it be?

Engine is a Yanmar 3JH2

[osprey877]

No fuelto Injectors could be any one or more of:
1. Injector pump drive slipping or seals leaking. Put a vacuum gauge on the line just before the pump and measure the suction.
2. Air lock or other blockage in fuel lines or injector or return line. Bleed the lines and/or clear any blockage.
3. Fuel tank not vented or located too low for pump to lift fuel. Raise the tank and make sure the vent is open.

[a64pilot]

Pull the HP pump and take it to a good repair shop.
Don’t try to start it again until you do

[andreas.mehlin]

Thanks

I have an extra set of injectors so I can try if those make any difference.
Otherwise I'll pull the injector pump.

[a64pilot]

If it went to high speed all by itself, it’s a governor problem, it isn’t injectors, it can’t be injectors.
Assuming the governor is in the pump, pull the pump before you blow the motor.

[zeehag]

might also want to take off head and peek inside... under pistons... just a helpful lil hint. mine looked great until it was taken apart then looked like a train ran over the erector set town. spectacular damages, impressed me much.
and all it said was ka lunk.

[SailngInTX]

To full RPM?
Could it have been a runaway?

[Scrimshaw4]

I agree that the runaway is typically caused by a governor problem. The non-restart may be due to the fuel solenoid in the injector pump. I'd investigate both before trying to restart. I''d add a fuel shutoff valve to your temporary fuel line so you can kill the engine if it runs away again. JMHO

[flyingnut40]

I had a V.W. Jetta that blew a turbo seal and the engine did a runaway and shutting off the ign. switch did nothing because it was running on its own engine oil. It would have continued running until out of crankcase oil if I had not choked off the air intake.
This would not happen if the engine was cold. so if it was on a palet and you were starting it to show someone that it ran, it would not be warm enough to run away on engine oil..... so the suggestions related to injector pump might make more sense.

[FionaJC]

FWIW I had a Turbo engine which just ran away. The Turbo bearings went so the oil from the crankcase was being pushed to the turbo bearings and as they didnt exist it went straight into the cylinders.

If went full revs it and created clouds of white smoke till it ran out of engine oil then seized.

[jimbunyard]

If the engine is on a pallet, do you know which lever is which? Typically there is a throttle lever and a shutdown lever. Could be that nothing is wrong at all, but it is important to know what's what when messing around with loose engines.

A64's right, it's nothing to do with injectors, don't waste your time there (other than to bleed them, if necessary). After sitting for 4 years, a stuck governor mechanism is possible and could be freed as easily as by the application of some spray lubricant and working the levers back and forth, or it could require complete disassembly and replacement of rusted or seized parts...

[Cpt Mark]

I'm taking a small marine diesel class right now and we covered this sort of last week.

We all know you need fuel, compression, timing to make a diesel run and a working governor if you want it to last. Unless you destroyed the engine you still have timing and compression which leaves...... drum roll please, fuel. Instructor who did this for over 40 years professionally stated that the top 4 reasons why a diesel won't start/run is in this order.
1. Fuel
2. Fuel
3. Fuel
4. Fuel

In 46 years of daily working with diesels he only pulled 2 injection pumps and of those, only 1 needed a rebuild.

It does sound like your governor has an issue and most likely as stated above it is corrosion. Spray it, disconnect the linkage if any (I have this issue on my throttles) move it back and forth, spray some more. Keep doing this until you can move it easily with your fingers. In the case of my throttle there is a spring return so I do this until that works as it should.

Your mechanical fuel pump also may not be working at minimum required pressure anymore. One way to check is to connect a Racor unit. If it's not pulling enough the razor will not be full when the engine dies.

[Library70]

I've seen diesel engines run away on starting fluid. Did you use any?

[Diesel Bill]

Just guessing without seeing in person. My guess is stuck rack inside H.P. pump/governor.
Easy enough to check and free it up. Don't restart till freed up.

[Sailorbob8599]

Originally Posted by Library70

I've seen diesel engines run away on starting fluid. Did you use any?

A run-away surely would require a continuous supply of fuel ... be it Diesel, or Engine Oil. I doubt it would be Starting Fluid, unless he sprayed the whole damned can full into the air filter housing or intake manifold but, there again, stranger things can happen I'm sure.