Runaway diesel engine.

[renewablejohn]

My little single cylinder 15hp Holder tractor decided not to start after putting it away for the winter at the end of October. Checked diesel pumping through to injector. Took injector out and wiped superficial soot off the end. When turning over produced plenty of chuffing smoke then after 10 minutes of trying to start with cold start button engaged it finally struck up with clouds of smoke and engine run away. Fortunately not much diesel in the tank but still very scary until it finally stopped itself after 3 minutes. No control whatsoever on throttle lever to shut it down.
Any advice what to do now. Engine still turns over and I have compression but no cold start button and no diesel being pumped to injector. Exhaust seems very oily.

 

[Dave]

You say no cold start, but could it be the cold start is stuck on? That would mean it was over fueling and running the way you say. Wouldn't worry to much about the oil in he exhaust, thats probably just unburnt fuel. As you say its is scary when an engine takes off like this and can cause damage, but6t if you've still got compression hopefully ok. id be looking at the injection pump, governor abd excess fuel set up.

 

[renewablejohn]

You say no cold start, but could it be the cold start is stuck on? That would mean it was over fueling and running the way you say. Wouldn't worry to much about the oil in he exhaust, thats probably just unburnt fuel. As you say its is scary when an engine takes off like this and can cause damage, but6t if you've still got compression hopefully ok. id be looking at the injection pump, governor abd excess fuel set up.

Good thinking I will go and check the cold start. As you say if it was stuck that would explain why the throttle not working.

 

[Ukjay]

Check your oil level too.

Runaway engines are usually showing signs that fuel has passed down through the rings and into the oil, thus raising the level in the sump - whereby the engine fires on the up and down stroke.

Very scary and extremely dangerous scenario....

 

[davieh3350]

Quite an interesting few minutes cracking the injector lines open on a runaway senator it was the extra fuel set up that had stuck open.

 

[renewablejohn]

Quite an interesting few minutes cracking the injector lines open on a runaway senator it was the extra fuel set up that had stuck open.

Braver man than me. First time I have seen a runaway and it was very scary. My reaction was big steps and often away from it.

 

[davidroberts30]

Braver man than me. First time I have seen a runaway and it was very scary. My reaction was big steps and often away from it.

RIP your jacket off and stuff it around the air intake

 

[Sharpy]

Or smash the glass bowl/stab the fuel filter/ cut a fuel line.

 

[Kevtherev]

Put your hand over the air cleaner I’ve had a major do it when the fuel pump rack stuck from standing.

 

[davieh3350]

Couldn't get at the air intake and as I had been bleeding it and the spanner was near enough in my hand I thought this was the best way. I kind of kept my head town a bit..

 

[Kevtherev]

Frightening when It happens

 

[TheTallGuy]

Jolly frightening when it's oil getting in - had it once with a failed turbo - the intake swallowed a t-shirt before the engine stopped.

 

[davidroberts30]

Or smash the glass bowl/stab the fuel filter/ cut a fuel line.

Wont work if it's running on its own oil

 

[Netherfield]

I had a Ford D series truck do it cold start stuck on the rack, had to take the pipe off the tank, it was the only thing reachable , I don't think it was over fueling just got the rack full open, still scary when it running full bore though, and you're down by the exhaust blasting at you.

 

[Morph]

Not sure if this would be similar. I had a Myanmar runaway in exactly the circumstances you describe minus removal of injector. In my case the simple injector pump seized in the wide open position ,after being stiff to move of stop. iyswim

Why Yanmar had to come out as Myanmar I don't know.

 

[Sharpy]

Wont work if it's running on its own oil

Yes, but the two cases I have been party to were stuck pumps, cutting the fuel worked fine, after speaking to a man I know with a Ford Cargo who stood and watched as his just fitted engine ran to destruction we have always had an emergency plan.

 

[davidroberts30]

Yes, but the two cases I have been party to were stuck pumps, cutting the fuel worked fine, after speaking to a man I know with a Ford Cargo who stood and watched as his just fitted engine ran to destruction we have always had an emergency plan.

Best practice is block air intake as that works for all eventualities

 

[Courier]

Similar can happen if oil bath air filter has been filled with too light a grade oil or diesel....

 

[Y Fan Wen]

Jolly frightening when it's oil getting in - had it once with a failed turbo - the intake swallowed a t-shirt before the engine stopped.

That's why you don't do what is suggested in post 9!

 

[Blue.]

I couldn’t get a seal onto the air intake due to it having a large mushroom type cleaner when my merc engine ran away,nothing I could do because I’d put the diesel pump back wrong and the stopper wouldn’t work.

It never ran again.