Diesel engine help

fordwheelinman said:
Does it run bad when it gets hot? Does it shut off while.iys running and wont crank back? Or does it run fine, then once you shut it off it wont crank back?

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It runs fine when it's hot. It just won't crank back up if I shut it off.

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Jeff B said:
Does this have a murphy hot engine shut down or low oil shut down? I looked through my kubota manuals. I don't have one for that engine.
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I think a low oil shut down. It has a engine oil pressure shutoff relay on it. I had an issue with a loose wire on it a while back, but I've checked all that. The relay clicks when I turn the key on, is that normal?

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Here's a picture of the relays.
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Danger_Ranger said:
It runs fine when it's hot. It just won't crank back up if I shut it off.

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After you get it warmed up, if you shut it off, will it crank right back up immediately, or does it sit for 10 mins then won't crank back?

When it doesn't crank, can someone crank the machine for you while you check to see if the fuel shut off solenoid clicks or if you get fuel coming out of the lines?

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fordwheelinman said:
After you get it warmed up, if you shut it off, will it crank right back up immediately, or does it sit for 10 mins then won't crank back?

When it doesn't crank, can someone crank the machine for you while you check to see if the fuel shut off solenoid clicks or if you get fuel coming out of the lines?

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No it won't crank right back up. I have to let it cool down before it will crank back up.

I can have somebody crank it while I check the shutoff solenoid and fuel lines.

I'm pretty sure it's getting fuel to the fuel rail. But I haven't pulled the injectors to check them yet.

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Danger_Ranger said:
No it won't crank right back up. I have to let it cool down before it will crank back up.

I can have somebody crank it while I check the shutoff solenoid and fuel lines.

I'm pretty sure it's getting fuel to the fuel rail. But I haven't pulled the injectors to check them yet.

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Go in sequence. First check to see if you have fuel making it to the injection pump.

Check to make sure the solenoid is working electrically. Use your hand to feel, or a pry bar against your ear to listen for the click when someone cranks it. If you think it works, unplug it and have them crank it again see if you have the same or different result.

If your confident it's working electrically, and you have fuel pumping up to the injection pump, loosen a fuel line at an injector, have them crank it, see if you get fuel squirting out. Be sure you lock the line back down before telling them to stop cranking.

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Use test light and see if you’re getting power to the fuel solenoid when key on and hot. Don’t use an LED test light, use an incandescent style. The fuel solenoid on my Kubota tractor (same engine) has a 5a fuse, so it’s not pulling a lot of amps to begin with. It sounds to me like there is a high current draw on the ignition circuit that is either heating the relay or the key switch but not enough to cause a shut down.

try swapping the K3 and K4 relays, then try disconnecting the oil pressure switch wire while hot and see if it starts. EOP (k3 relay) is Engine Oil Pressure shutdown. oil is thinner when hot, but its still flowing, oil pressure switches go bad, I see it and replace them all the time.


From my service manual for my tractor
Screen Shot 2020-05-31 at 10.46.09 AM.png


from Ditch Witch manual of similar machine, but newer
Screen Shot 2020-05-31 at 10.58.28 AM.png

Screen Shot 2020-05-31 at 10.59.04 AM.png
 
Ok, I'll give that a shot. If I can find my test light lol. But I'm pretty sure the eop relay is working because when I found the loose wire on it it would run as long as I had the starter going, but when I let off the starter is would stop running. Found the loose wire, connected it back and it fired right up. Should the fuel shut off solenoid work when I turn the key on or just when I turn the starter over? I'm pretty sure mine only clicks when I turn the starter over. I don't hear or feel anything when I just turn the key on.

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Danger_Ranger said:
Ok, I'll give that a shot. If I can find my test light lol. But I'm pretty sure the eop relay is working because when I found the loose wire on it it would run as long as I had the starter going, but when I let off the starter is would stop running. Found the loose wire, connected it back and it fired right up. Should the fuel shut off solenoid work when I turn the key on or just when I turn the starter over? I'm pretty sure mine only clicks when I turn the starter over. I don't hear or feel anything when I just turn the key on.

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fuel solenoid should open anytime the key is in on position. you may not feel it click. If EOP isnt powering the fuel solenoid won't open.

in post 12 on this thread, you show a connecter with a looped wire, that's the backhoe option remote, make sure those wires have good connection (22 on on side 13 on the other see schematic )

the starter function in key switch over rides EOP to allow oil pressure to build and allow engine start. You may be having issue with the Start Bypass timer too
 
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Ok so just tested the fuel solenoid wires with key in on position, now power. It gets power when I turn the starter over. Is that the way it's supposed to be?

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Danger_Ranger said:
Ok so just tested the fuel solenoid wires with key in on position, now power. It gets power when I turn the starter over. Is that the way it's supposed to be?

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it should get power and hold power for 5 seconds after start to allow for oil pressure build and the switch and EOP to take over. disconnect the oil pressure switch and try it again ( switch is normally closed, which means circuit is powered to open EOP relay and not allow fuel ) disconnect the switch that should kill the power to relay and light and allow start. Oil pressure switches switch to ground, which completes a circuit to turn on light and other items ( EOP in the case )

if you look, every wire has a number printed on it at each connector termination, these are the identifiers on the schematic

It will start and run while in start as the fuel solenoid is powered Pull in on start, Hold in is powered thru EOP relay and that's what keeps it running. ( see schematic fuel solenoid ) Sa is pull in power, 22 is hold in power, 13 is the wire you need to find at the EOP relay. 13 jumpers to 22 at that connector you showed in a previous picture. ( see numbers on each end of wire )

each wire on the fuel solenoid has a function, its not hot and ground, solenoid grounds thru body to engine

you should have power into the EOP relay on wire 8 running or not with key on.

disconnect the oil pressure switch and the EOP should pass power with key on, if not the relay may be bad, even if it clicks it can be bad.

Kubotas have a history of failing oil pressure switches.
 
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Ok I've tried all that and everything checks out. This was done with the engine cold. Should I try it when the engine is hot also?

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Danger_Ranger said:
Ok I've tried all that and everything checks out. This was done with the engine cold. Should I try it when the engine is hot also?

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Yes, that’s when you’re having the issue.
 
Well....I think it's fixed. While tracing the wires out for the eop relay I seen one of the wires had a little skinned place in it, so I put some electrical tape on it. I swapped the eop relay and light test relay. Ran it around the yard a little bit and got it hot, cut it off and it fired right back up. I tried it a few times and it fired up. Not sure if it's the relay or the skinned wire that was the problem. I hope that's all it is anyway. I'll keep running it and see if it still acts right. Thank you everyone who helped, I couldn't have done it without you that's for sure.

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