BX22 immediately turns off after start
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DiezNutz
Veteran Member
Tom_H
Veteran Member
If it's instant shutoff upon releasing key, I'd guess fuel solenoid or switch kickback as described by Bird.
If it fires another rev or two after that, and then dies, I'd check fuel filters. My VW diesel Rabbit pickup had this problem once. After shutdown, enough fuel seeped back in for a restart. As soon as the engine fired for a few revs, the pump coundn't draw fuel through the clogged filter fast enough and it would stall. Less likely, though possible, is an air filter so badly clogged that not enough air is being drawn in through the intake valves. In either of these cases, I'd expect to hear knocking and to feel a strain on the entire crankshaft system.
This is nothing new to most people on this site, but for those not familiar with diesel engines, a diesel doesn't have an "ignition" system, only a "starter" system. The compression stroke builds a much higher compression ratio than a gasoline engine. Following the Ideal Gas Law, PV = NKT, the rapid high compression builds so much heat that when the fuel is injected, the high temp of the compressed air causes instant oxidation with no spark or spark plug necessary to "ignite" the fuel and oxygen. Glow plugs (and block heater in winter), provide the extra heat needed when the block is cold. The starter turns the entire crankshaft, pistons, rods, for the first couple of revs until the first couple of explosions occur. After the key is released, the starter disengages and the inertia of the crankshaft, and pressure from expanding gasses in the other cylinders, is enough to drive each succeeding compression stroke through subsequent injection and burn.
If it fires another rev or two after that, and then dies, I'd check fuel filters. My VW diesel Rabbit pickup had this problem once. After shutdown, enough fuel seeped back in for a restart. As soon as the engine fired for a few revs, the pump coundn't draw fuel through the clogged filter fast enough and it would stall. Less likely, though possible, is an air filter so badly clogged that not enough air is being drawn in through the intake valves. In either of these cases, I'd expect to hear knocking and to feel a strain on the entire crankshaft system.
This is nothing new to most people on this site, but for those not familiar with diesel engines, a diesel doesn't have an "ignition" system, only a "starter" system. The compression stroke builds a much higher compression ratio than a gasoline engine. Following the Ideal Gas Law, PV = NKT, the rapid high compression builds so much heat that when the fuel is injected, the high temp of the compressed air causes instant oxidation with no spark or spark plug necessary to "ignite" the fuel and oxygen. Glow plugs (and block heater in winter), provide the extra heat needed when the block is cold. The starter turns the entire crankshaft, pistons, rods, for the first couple of revs until the first couple of explosions occur. After the key is released, the starter disengages and the inertia of the crankshaft, and pressure from expanding gasses in the other cylinders, is enough to drive each succeeding compression stroke through subsequent injection and burn.
WaynePeterson
New member
My BX22 did exactly the same thing yesterday evening.
Okay, I worked the little guy hard all weekend (moved mulch and gravel, cut a short piece of road into the uncleared part of the property and spent most of Saturday doing that and starting the long-neglected clearing, dropped the FEL and BH yesterday, remounted the MMM and started mowing).
After about 45 minutes of mowing yesterday evening, it cut out completely. Repeated attempts to restart it were fruitless, and the little fellow is still sitting in the middle of one section of lawn, forlorn, in full view from the road, amusing the neighbors. (One has already knocked on the door, wanting to talk about the breakdown. Downside of working from home.)
Diagnostics: (turned here second when the Kubota shop manual was completely silent on the issue).
Both fuel filters are new, so is the air filter.
Panel lights are on in the "on" position.
It will start and run only so long as I keep the key in the "start" position.
Conclusion: fuel and air aren't the problem.
Solenoid fuse (20A yellow) was blown.
Installed another one, it blew.
Sounds like the solenoid is at fault rather than the main switch. Heading to the dealer to get one.
My question: Where the heck is the solenoid mounted?
Under the seat?
Engine compartment?
Electrical panel in front of my knees, near the battery?
Please just tell me is ISN'T mounted underneath, near the second fuel filter.
Thanks very much for the help.
Okay, I worked the little guy hard all weekend (moved mulch and gravel, cut a short piece of road into the uncleared part of the property and spent most of Saturday doing that and starting the long-neglected clearing, dropped the FEL and BH yesterday, remounted the MMM and started mowing).
After about 45 minutes of mowing yesterday evening, it cut out completely. Repeated attempts to restart it were fruitless, and the little fellow is still sitting in the middle of one section of lawn, forlorn, in full view from the road, amusing the neighbors. (One has already knocked on the door, wanting to talk about the breakdown. Downside of working from home.)
Diagnostics: (turned here second when the Kubota shop manual was completely silent on the issue).
Both fuel filters are new, so is the air filter.
Panel lights are on in the "on" position.
It will start and run only so long as I keep the key in the "start" position.
Conclusion: fuel and air aren't the problem.
Solenoid fuse (20A yellow) was blown.
Installed another one, it blew.
Sounds like the solenoid is at fault rather than the main switch. Heading to the dealer to get one.
My question: Where the heck is the solenoid mounted?
Under the seat?
Engine compartment?
Electrical panel in front of my knees, near the battery?
Please just tell me is ISN'T mounted underneath, near the second fuel filter.
Thanks very much for the help.
Last edited:
WaynePeterson
New member
::: sigh :::
"D'oh!" (Channeling Homer Simpson here today).
The solenoid is, of course, mounted to the injector pump. Where the heck else would it be?
"D'oh!" (Channeling Homer Simpson here today).
The solenoid is, of course, mounted to the injector pump. Where the heck else would it be?
hazmat
Elite Member
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- Kubota L5460HSTC
injector pump is on the engine. follow the fuel line from the filter towards the engine. stop before you get to the dohicky that splits off into 3 lines going to the cylinders. between the filter & the dohicky will be the solenoid.
Volfandt
Veteran Member
WaynePeterson, did you follow the fuel shutoff solenoid troubleshooting schematic I posted in post #8?
The reason I ask is that it could be something else blowing the fuse. You got anything connected to that "hot" wire under the seat?
You may even unplug the solenoid, replace the fuse and see if ti blows again.
In any case good luck.
The reason I ask is that it could be something else blowing the fuse. You got anything connected to that "hot" wire under the seat?
You may even unplug the solenoid, replace the fuse and see if ti blows again.
In any case good luck.
rdsaustintx
Veteran Member
Volfandt said:
+1 Good advice.
WaynePeterson
New member
Gentlemen,
Thanks for the good counsel. I replaced the solenoid late yesterday evening, installed a new 20A fuse, and the tractor fired right up.
The old / bad solenoid appeared to have worn around the plunger. No wonder ... given that it is going to get a lot of abuse from engine heat. I was surprised that it would fail at 220 hours until I saw how it was mounted and operates. I understand that in the new models it isn't mounted in the same fashion.
So, thanks very much to all. The little 'bota rides again.
Wayne
Thanks for the good counsel. I replaced the solenoid late yesterday evening, installed a new 20A fuse, and the tractor fired right up.
The old / bad solenoid appeared to have worn around the plunger. No wonder ... given that it is going to get a lot of abuse from engine heat. I was surprised that it would fail at 220 hours until I saw how it was mounted and operates. I understand that in the new models it isn't mounted in the same fashion.
So, thanks very much to all. The little 'bota rides again.
Wayne
