runaway rtv900 engine???????

[rtv9001]

so sadly, as the title says I all of a sudden had an issue with my rtv where it was way down on power like fuel was being restricted, so while I was trying to diagnose I started and stopped the engine a few times.
Well, on the last and final time the thing ramped up to max rpm, spewing black smoke, wouldn't shut off with the key and I eventually had to crack the fuel lines right at the injectors until it lost fuel pressure and stalled.

Hoping somebody might have some experience with this issue and could direct me to a specific part?
I'm assuming the actual high pressure pump is working fine since it ran away, so I guess whatever is supposed to meter the amount of fuel has failed? I just don't really know what part that would be on this.

 

[thepumpguysc]

The inj pump controls the amount of fuel sent to the injectors, the injectors atomize the fuel into a mist where the mist is “exploded” in the cylinder caused by the heat generated from the glow plugs and pistons going up and down..
That said, I would suspect the control rack on the inj pump is stuck wide open..
If your shut off solenoid is screwed into the left hand side of the inj pump “block”, u can disconnect it (1wire) and unscrew it from its home.
Now reach in and see if u can move the rack with your finger.. or a pick..
A lot of times there is an access cover on the engine directly on the side of the inj pump..
U can remove it and gain access directly to the control rack.. see if u can move it left and right..
Good luck.

 

[rtv9001]

so I just talked to a tech at a tractor dealer near me. He thought it sounded like it cracked a barrel in the pump?
And replacing the pump assembly itself would be the solution?
My shut off is on the right side of the pump when looking down at it, toward the front of the vehicle. I even pushed that shut off lever myself and it did nothing to cut fuel. But mine doesn't seem to have any access cover so not sure if maybe it's a different design?
It's a 2010 rtv900
I could get a picture if that would help?

 

[thepumpguysc]

A picture would be GREAT..
I wonder how many times they used THAT line.!!??

 

[rtv9001]

 

[rtv9001]

so here's my injection pump
governor, power control is on the right of this.
the top lever with the red screw is the fuel kill, which of course did less than nothing even when I manually pinned it on it's stop.
so bottom line I don't know otherwise how the fuel is controlled in this unit.
I did change an injection pump on an rtv probably 15 years ago but I do remember it's basically a rectangular canister shape that slides down into the opening to rest on 3 cam lobes that do the pumping. Other than that I don't recall much nor how you even prime one of these things without just endlessly cranking the motor

 

[Sawyer Rob]

You stop a runaway diesel by blocking the air supply, a rag works good for this.

SR

 

[thepumpguysc]

U have it correct, it’s the same as your previous job.
Bolts on the 4 corners..
U might have a slight problem if the rack is stuck, only because the rack has to be in a certain position to allow the rack pin to pass..
There’s actually a CUT OUT in the block to allow it to pass..
Do yourself a favor and watch some videos… they’re all basically the same..
Kubota has some decent ones.. your pump is called a PFR PUMP..

 

[rtv9001]

yeah I tried searching for videos and can't find crap.

bottom line, I'm assuming at this point you agree it's the pump assembly itself that has a failed part and I need to swap that whole part out?
or am I wrong and it may be something else?
I'm certainly no expert on these machines. I understand the fundamentals but I have pretty limited experience actually working on these engines. The pump is expensive as hell so I'd hate to throw that money at it and have a runaway again. However this time I'm going to have a C02 fire extinguisher ready on hand so I can stop it instantly.

 

[mike0000]

This is a D722 3 cylinder not sure how close the IP’s are to the RTV’s