G1800 cranks , won’t fire

[Henro]

One uneducated thought I have is I wonder if although the fuel shutoff solenoid seems to be moving properly, might the mechanism it controls inside the injector pump be hanging up?

Cannot help but remember the old saying about the first three letters in the word when we make assumptions.

 

[Soonerdad]

I guess anything is possible.

 

[Torinodan]

These pumps are actually not bad to disassemble. The pistons/rollers could be stuck or the springs are broken to return them to the cam. Find pics and diagrams. Good videos online as well, most of these all work the same. Remove the pump assy and take us pictures of it removed so we can see the bottom.

 

[lugbolt]

rack could be stuck in "off" position, although I can't see it being likely. You can check it though. Remove the throttle cable bracket and under it I think is a small metal plate held on by 2 more screws. Remove the plate. Now you can see the rack and also part of the fork lever. See if you can manually move the rack back and forth. I can't remember on these if that's possible...I think it is. You can also see the rollers and the fuel cam if I remember right. If you can, have a look at them. If you see a gap between the roller(s) and the cam, the plungers are stuck. Any gasoline or water in the fuel can cause this.

another thought. Before deeming the pump to be "not pumping" remember this. The injector pump can't pump anything if it ain't getting anything to pump. What I'm sayin is, fuel needs to be getting up to the pump; I'm assuming you've already loosened the bleed screw and you have fuel spraying out with the key on. It should more or less spray and not really dribble.

 

[Soonerdad]

rack could be stuck in "off" position, although I can't see it being likely. You can check it though. Remove the throttle cable bracket and under it I think is a small metal plate held on by 2 more screws. Remove the plate. Now you can see the rack and also part of the fork lever. See if you can manually move the rack back and forth. I can't remember on these if that's possible...I think it is. You can also see the rollers and the fuel cam if I remember right. If you can, have a look at them. If you see a gap between the roller(s) and the cam, the plungers are stuck. Any gasoline or water in the fuel can cause this.

another thought. Before deeming the pump to be "not pumping" remember this. The injector pump can't pump anything if it ain't getting anything to pump. What I'm sayin is, fuel needs to be getting up to the pump; I'm assuming you've already loosened the bleed screw and you have fuel spraying out with the key on. It should more or less spray and not really dribble.

Yes. Plenty of fuel to the bleed screw. I just had a thought run thru my head. I recently turned up the fuel about 4 turns . Wonder if that had an effect? I’m grasping here

 

[lmichael]

I am on the side of the fuel shutoff. IDK, diesels typically just simply "don't work" after a shut down. And mechanical things don't typically just "not work" as in the injector pump.

 

[Soonerdad]

Yes. Plenty of fuel to the bleed screw. I just had a thought run thru my head. I recently turned up the fuel about 4 turns . Wonder if that had an effect? I’m grasping here

Yes. Plenty of fuel to the bleed screw. I just had a thought run thru my head. I recently turned up the fuel about 4 turns . Wonder if that had an effect? I’m grasping here

so that I am on the same page , are you talking about what’s circled in yellow?

 

[lmichael]

so that I am on the same page , are you talking about what’s circled in yellow?
View attachment 88820

That is the fuel shutoff or engine stop lever. Though unsure who your question was directed at

 

[Soonerdad]

That is the fuel shutoff or engine stop lever. Though unsure who your question was directed at

It was directed at lugbolt

 

[Soonerdad]

Yes. Plenty of fuel to the bleed screw. I just had a thought run thru my head. I recently turned up the fuel about 4 turns . Wonder if that had an effect? I’m grasping here

Lugbolt said to remove the throttle cable bracket to get to a plate. Is the bracket in yellow?

r

 

[lugbolt]

yup

and yes the stop lever is circled in the pic above. The stop solenoid is attached to the stop lever. When solenoid is energized (when you turn the key off or fall out of the seat-assuming the switches and combination box work properly) it pulls the stop lever which moves the rack in the pump to "off". Kills fuel flow through the pump.

With that said you can infer that there are several possibilities. Stop solenoid, sticking stop lever, wiring, combination box, and fuel injection pump. Then you have your supply side which you've already addressed, said you have flow at the bleed screw.

Sometimes the stop circuit can get fouled up. I've had some of them where the solenoid appears to work fine and it is sticking a little, holding up fuel flow. If that is suspected I'll disconnect the solenoid from the harness, and then manually (with my finger) grab the little philips head screw on the stop lever and move it either ON or OFF. If you look at the lever and how it operates you'll see it's stops. It should go fully against both, one stop is off and the other is "on".

 

[lmichael]

I solved the whole issue with the stop solenoid. Removed it and installed an actual stop knob. When I want to stop my engine I turn off the key, and pull my stop knob. (looks like a choke knob). Engine stops and release knob, spring loaded and returns to run. EZPZ no electronics for me

 

[Soonerdad]

Update; pulled the lines at the pump. Cranked motor and very weak shot of fuel out of all three ports. Pulled the injection pump. Rack isnt stuck. Referred to fuel injection place by local Kubota dealer. supposed to be very very reasonable on pricing . sending it off on Monday. Will probably go ahead and put new injectors in it after pump rebuild. Will update

 

[lmichael]

Seems a bit extreme. Remembering back to your original post. IIRC, it was running, you shut it down, then would not restart?

 

[Soonerdad]

Well, I’ve screwed with it now for 2 weeks on and off. Fuel pump works. Fuel to the bleed screw. Solenoid working as supposed to. No fuel to the injectors. Weak flow out of pump with lines removed.
common sense says of everything else is working as supposed to with fuel into tHe pump but no fuel out of the pump ……..it’s the pump.

 

[lugbolt]

those pumps don't move much fuel. So if you pull a line off and "check for flow" you won't get very much. A very, very thin stream is about it. On those little engines like that it's much better to use an actual pressure measurement.

if you can get to the side inspection plate look at the rollers on the pump in relation to the camshaft. If the rollers have clearance the plungers are sticking/stuck. They should have 100% contact with the cam lobes.

 

[Russell King]

Sounds like the OP has pulled the pump off already and may have taken it to the repair shop already.

Hopefully they can get him a known good pump back and that was the problem.

Is there any chance that the engine drive mechanics to the pump would fail?

 

[Soonerdad]

Sounds like the OP has pulled the pump off already and may have taken it to the repair shop already.

Hopefully they can get him a known good pump back and that was the problem.

Is there any chance that the engine drive mechanics to the pump would fail?

‘yes , pulled the pump Friday evening. Boxed it up and should be in Ft. Smith by Tuesday. It’s worth a few bucks to get it looked at and determine if it’s the pump or not once and for all. All indicators are pointing that direction. As far as the drive mechanics, it’s possible yes. However , with pump pulled, I tapped the starter for an instant. Just enough to get a split sec movement of the mechanicals. Fuel camshaft moved ever so slightly . So that’s not it thank god.

 

[Russell King]

Thank you for the feedback.

I assume you’re aware of the shims between the block and injection pump and are keeping up with them?

 

[Soonerdad]

Thank you for the feedback.

I assume you’re aware of the shims between the block and injection pump and are keeping up with them?

Got them all…..three I think