743 was having hard time starting and had power loss after operating awhile. I checked the glow plugs, 3 were open, no resistance. replaced glow plugs. noticed water in fuel bowl so drained tank. lots of water. looked for tank strainer did not find. fuel filter had dirt in bottom went to bobcat and got filter. the filter they gave me did not look the same. old filter did not have slits in top and bottom. the top o ring was not on internal shaft of filter assy. put on new filter, fresh fuel, removed air still would not start. turning good, white smoke, voltage to glow plugs. tried heating intake no good. removed high pressure lines from delivery valve nuts which i had out for front glow plug. cranked engine and no fuel came from the pump. getting fuel to return and valve and inlet hose to pump. when i crank engine no fuel from delivery valve nuts. if i loosen nuts fuel squirts out. this unit has been using starting fluid for a while. not sure how fuel pump works but i have a service manual. compression????
wont start
- Thread starter tnt
- Start date
skidsteer.ca
Well-known member
- Joined
- Jan 20, 2006
- Messages
- 3,853
If you have smoke while cranking then the injection pump must be squirting it through the injectors into the cylinder. Any idea how many hours are one the engine?
Could be worn out injectors that are not atomizing the fuel. If you remove the injectors you can attach them to the injection lines and observe the spray pattern while cranking the engine. Or take them to a injection pump shop and have them crack tested.
Or low compression. If you give it a sniff of either will it fire or start? Word on the street is 4000 to 5000 these Kubotas lose some of their compression and get harder to start.
You could add a block heater if you don't already have one.
Ken
Could be worn out injectors that are not atomizing the fuel. If you remove the injectors you can attach them to the injection lines and observe the spray pattern while cranking the engine. Or take them to a injection pump shop and have them crack tested.
Or low compression. If you give it a sniff of either will it fire or start? Word on the street is 4000 to 5000 these Kubotas lose some of their compression and get harder to start.
You could add a block heater if you don't already have one.
Ken
Silly question, but have you left the stop cable up?
As Ken did point out, white smoke means fuel, but it could be fel thats been sitting. As you did mention that you were not getting any fuel from the delivery valves it sounds to me taht you have not got prime yet or you have the stop cable pulled out preventing fuel from coming out.
You did prime it correctly? open the valve on the pump and use the primer bulb till it felt firm? then closed it?
