Kubota RTV 900 cranks, but wont start

njfontana

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Kubota RTV 900
Aug 22, 2018
4
0
0
Chepachet, RI, USA
Hi, I have a 2004 Kubota rtv 900 with 2200 hours on it. recently while using it we shut it down and it wouldn't start again. it will crank and turn over but wont start. ive gone through it a bit already and found that the injectors weren't getting fuel so i replaced the old fuel filter and went to bleed the lines at the injector pump but no fuel came out. so i took the fuel pump off cleaned it out and still no luck. could the fuel pump suddenly stop working like this? i cant find any other info on it and even the pump itself seems to be hard to come by. any help is greatly appreciated. thank you.
 

D2Cat

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Re: Kubota RTV 900 turns over but wont start

If you have power to the lift pump but no fuel come from the discharge side of the pump, you have a pump that is not pumping (that is if you have fuel in the tank!).

To answer your question, yes a pump can just quit working.
 

100 td

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Re: Kubota RTV 900 turns over but wont start

Fuel shut off solenoid or control of that solenoid is also possibility. If you don't have a win with other checks, consider looking into this one. Do you have a service manual with an electrical schematic in it, post it up if you do.
 

lugbolt

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Oct 15, 2015
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Re: Kubota RTV 900 turns over but wont start

Lift pump is mechanical on those. No power to it, runs off of the fuel camshaft sorta like an old domestic V8.

Never bleed the system at the delivery valves. Meaning at the injector lines/pump side. It's too easy to turn the delivery valve in the pump when trying to loosen the pipe nuts...and when it does turn, it'll never run correctly until the pump's rebuilt and then re-timed. It's real easy to do it too and most times you never even know the delivery valve has turned until it does start/run and then runs like poo. Just an FYI.

There is a hex bleeder near where the rubber fuel line enters the injection pump. Bleed it there. Loosen the hex, crank engine until fuel comes out, tighten bleeder, then start the engine. It may take some cranking if it has a lot of air in it. IIRC the hex bleeder is 10mm on the old 900's.

Here's how I diagnose a no-fuel situation. Loosen hex bleeder at the injection pump, then crank engine. With the bleeder loose, it should pump some fuel out and make a mess. If it doesn't, either there is a restriction between the injection pump and fuel tank, or the lift pump (little mechanical pump) is bad....but those lift pumps aren't known to fail very often and a lot of times when they do, it fills the crankcase with fuel. Is the oil level higher than normal? IF you do get fuel there and it won't start, check your fuel shutoff solenoid. Some of them had a "large" solenoid mounted atop the injection pump area totally exposed. If you have one of those, I've seen more than one of them die...get stuck in the "off" position, and when they do, the engine will not start until a pair of fingers (yours) manually push the shutoff lever back to "run". If you have an internal solenoid...which is mounted on the back side of the engine block where the injection pump is, there's not much you can do with it...if it clicks when you turn key on, it's likely good, if not, check for power and proper ground. If no power, follow the circuit to find out why using your wiring diagram.
 

njfontana

New member

Equipment
Kubota RTV 900
Aug 22, 2018
4
0
0
Chepachet, RI, USA
Re: Kubota RTV 900 turns over but wont start

Thank you for the response! I’ve been out of the state and haven’t had a chance to look at it but now I’m back. I’ve checked the solenoid and it does click on when I try starting it and off when I shut it off so that seems good. I pulled off and blew out the fuel lines and even drained the tank and filled with new fuel. The fuel flows fine out the tank through the filter and into the pump but when I try bleeding the System at the hex nut I still get nothing. I checked the oil and it was actually low and dirty so I did a filter and oil change. Is there more to this fuel pump that I might be missing? It seems so simple and I don’t want to blow my starter by cranking it all day. Not sure what to do next. I can order a new fuel pump but when I took the fuel pump off and cleaned it it would actually pump fuel by hand so it seems ok. Very weird.
 

njfontana

New member

Equipment
Kubota RTV 900
Aug 22, 2018
4
0
0
Chepachet, RI, USA
Re: Kubota RTV 900 turns over but wont start

Ok I’ve replaced the fuel lines and clamps and it seems I have fuel flowing now. When I crank it it wants to start but doesn’t. It’s blowing whitish smoke out the exhaust. What could cause this?
 

North Idaho Wolfman

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You have air in the lines, you must bleed all the air out at the injectors. ;)