FLU419 Diesel engine does not shut off

[ede356]

Hello all,
I run in a weird situation a few days ago: one of my FLU419's did not shut off even after I put the hand throttle in off position.
I heard of situations like this on Mercedes diesel cars when they have an issue with the vacuum shut-off valve. But the Flu419 does not have a vacuum line to shut off.
Not only that the engine didn't shut off it also rev'ed up. The only way to stop it was cutting off the fuel.

Has anybody had a situation like this before? Any hint, what causes that issue and how to fix it?

Thanks

Ede356

 

[Speedwoble]

Your throttle linkage was likely bent, which will cause it to go overcenter and increase the throttle. I believe this happened on a prior FLU I had and I was able to pull up the foot throttle to shut it off. Check the linkage on the engine side of the firewall by the foot and hand throttle. This is covered somewhere in the main owner thread.

For future reference, you can shut the engine off by putting it in high gear and stalling it or by reaching above the Passenger side tire and directly actuating the shut-off on the IP. Both are easier on the IP than starving it of fuel.

One last option is if you tried to pull something solid and pushed the clutch in right before stall. The engine can actually run in reverse. But it will sound different as it is sucking air in the exhaust and out the intake. In this case, you must stall it to kill it quickly as it is running without oil pressure.

 

[ede356]

Speedwoble,
thank you for your advise.
The linkage is not bent.
I even took the engine cover inside of the cabin off and actuated the lever so that it went in its "Off" position...

Where do I find the shut off on the IP?

 

[Speedwoble]

It is the same as the throttle, just pulled the opposite way.

 

[SeeNebraska]

this just happened to me tonight. only thing i could think to do was close off the fuel line with the valve by the tank. also tried to cover the intake air at the same time. Eventually it died but it took a while and was running very high RPM's. since i dont know what caused this, i'm nervous to go start it back up again...

 

[monstermog]

So the linkage wasnt over center. When the engine cover is off...look at the left hand side of the engine by the throttle. Is the plastic roller stuck in the wrong position?

In actuality the engine and cab are seperate from eachother thats why there is a ramp up on oneside.

Also in this is the high idle pnematic ram for the rear. If the switch is on in the rear it will activate this ram too idle high. Hit the switch on your controls in the backhoe and you should have independent control again.

 

[911joeblow]

Make sure you dont have low engine oil! You might be sucking pan oil into the combustion chambers or pressurized oil past a head gasket. This is a REALLY bad condition that have caused some VERY serious destruction. This is the first thing I check if I cant shut off a diesel.

 

[swpa90]

Hello all,
I run in a weird situation a few days ago: one of my FLU419's did not shut off even after I put the hand throttle in off position.
I heard of situations like this on Mercedes diesel cars when they have an issue with the vacuum shut-off valve. But the Flu419 does not have a vacuum line to shut off.
Not only that the engine didn't shut off it also rev'ed up. The only way to stop it was cutting off the fuel.

Has anybody had a situation like this before? Any hint, what causes that issue and how to fix it?

Thanks

Ede356

Hi! This is my first time posting to this site. I just purchased 2 SEE's and am getting them both running. I managed to get first one working today and it was literally the same exact issue you stated. The weird thing for me is that i did cut the throttle off and and checked the pedal as well and mine was stuck on high for awhile.
Definitely am nervous to start up again..as i did not see any linkage problems
Did you find out what the issue was?
Any advice how i should move forward
Thanks

 

[glcaines]

The first thing is to pull the cover off the engine and check the linkage. Make certain that nothing is bent and that the linkage moves freely. If you have a bent rod, rusty or broken springs, replace them. I thoroughly lubed my linkage, replaced the rod and all springs. If everything looks OK and the linkage moves freely, start it with the cover off. With the cover off, you can manually shut the engine down by moving the linkage at the IP by hand. It is somewhat confusing to adjust the linkage correctly, but the TM explains it. When you push the plastic handle forward to the stop, the engine should shut down. You shouldn't have to move it sideways and push it past the stop to shut the engine down if everything is adjusted correctly.

 

[swpa90]

The first thing is to pull the cover off the engine and check the linkage. Make certain that nothing is bent and that the linkage moves freely. If you have a bent rod, rusty or broken springs, replace them. I thoroughly lubed my linkage, replaced the rod and all springs. If everything looks OK and the linkage moves freely, start it with the cover off. With the cover off, you can manually shut the engine down by moving the linkage at the IP by hand. It is somewhat confusing to adjust the linkage correctly, but the TM explains it. When you push the plastic handle forward to the stop, the engine should shut down. You shouldn't have to move it sideways and push it past the stop to shut the engine down if everything is adjusted correctly.

Hey, thanks for the reply. I wd40 both linkages on both units for a few days before starting they were definitely a bit rusting. But they move back and forth. Im at a bit of a pause. The one that was idling high, doesnt want to start up again. Fuel primer stays nice and tight, no lose of pressure.
The second units stays on for awhile, then turns off and it takes a minute to get back on.
Kinda stumped on what to do next.

 

[govsurplus]

Check the switch for the hyd tools that will also cause high Idle, First time I had a similar problem after sitting for ten-plus years the engine was slow to build air pressure when it started to work the air pressure caused the high idle to work, while its running bleed off the air tanks it will shut off with the handle,

 

[roverchef]

@govsurplus
Always good to bring back a yr old thread.

 

[Copout911]

@govsurplus
Always good to bring back a yr old thread.

Hey, thanks for the reply. I wd40 both linkages on both units for a few days before starting they were definitely a bit rusting. But they move back and forth. Im at a bit of a pause. The one that was idling high, doesnt want to start up again. Fuel primer stays nice and tight, no lose of pressure.
The second units stays on for awhile, then turns off and it takes a minute to get back on.
Kinda stumped on what to do next.

Repost if you ever figured out the cause of the issue as I recently bought an FLU419 doing the exact same thing. I suspect a common issue and we all could benefit a fix. Thanks in advance

 

[Copout911]

Good Moring all, New (ish) here,

So as stated in the reply just above I recently purchased an FLU 419 that has been sitting for years, How Many is undetermined. The first few things I did was do a fluid check and all seemed ok. I then installed fresh charged batteries to start it. After troubleshooting the start button finding a bad relay just located by the fuse clusters. I then got the engine to start with a bump of ether and it seems to bust right off but at very high RPMs and would die if you didn't stay 3/4 to wide open throttle. It did seem underpowered and would fall off not idle down. an interesting observation is that I could rev it up and down between 1600 RPM and 2500 RPM with the foot peddle and sometimes it would return and sometimes not, it would stay at high revs. The linkage to the hand lever and foot peddle have been lubed/checked all the way to the injection pump and is free to move and return. While I do work/play with many types of engines but learn from all and don't know it all. My thought is this engine wouldn't run starving for fuel, but I cleaned/checked the prefilter screen to find nothing of consequence as well as checked/cleaned the two cartridge filters again with nothing notable, i also drained and put new clean diesel in the tank. After priming I get the exact same results. I would love for someone who has experienced this prior to chime in with a fix as it seems this is a common issue as posted by several people but non offered the solution as happens a lot after one's problems are fixed. Please offer and ideas from experiences of your own.

 

[Copout911]

An update to my Unimog condition,

So after digging in to trouble shoot my situation, I discovered that the #4 element in the injection pump was stuck in the up position. What this done was caused #4 cylinder a "dead hole", secondary with the element stuck caused the injection pump rack to not be able to close to fuel shut off and caused the pump to continue to fuel with all linkages in the off position. Of course it makes sense now but took some digging into. With that said and now I know what to look for, it isn't an uncommon condition for these units, when bring them back alive. While not really preventable as it was a condition upon me taking possession, I highly suggest checking the condition of all filters and fluids to make sure you give it the best chances possible to work as intended. On to the next issue... Carry on!

Paul

 

[NY Tom]

Thanks for coming back to explain your problem and the resolution.

 

[peakbagger]

The Unimog "expert" I bought my 1300 from and who had recently bought two FLU419s a few years ago suggested that the filters be drained and filled with injection cleaner prior to the restart of engines that had been sitting around. He then primed the system until the relief valve lifted in the injection pump so that the fluid had completely flooded the injection pump and then let it sit for awhile. He felt that that would break down any deposits in the pump and injectors.

 

[Copout911]

The Unimog "expert" I bought my 1300 from and who had recently bought two FLU419s a few years ago suggested that the filters be drained and filled with injection cleaner prior to the restart of engines that had been sitting around. He then primed the system until the relief valve lifted in the injection pump so that the fluid had completely flooded the injection pump and then let it sit for awhile. He felt that that would break down any deposits in the pump and injectors.

Agreed that sounds like a good idea of sorts. I wasn't sure I was going to post how I fixed mine as it is now running (engine) as it should. While crude (ish) I used a brass punch and tapped the element down after removing the delivery valve. I can't say I would recommend doing this to others, but with a little common sense and feel for what you are doing it obviously can be done with success.

I did however run into a perplexing problem to be sorted next. when out "test" driving it on the back property I noted that as soon as I would depress the clutch it would act as if the brakes were applied yet roll downhill when in neutral. I am crossing my fingers that the shifter bushings will have some affect as others have complained of the same issue so it hopefully isn't unique to mine and someone that has experienced this can help.

 

[87cr250r]

Detroit Diesel used to have a shutdown air damper for stuck rack situations due to an injector getting stuck. Perhaps you should consider the same?

4262C Air Shut Off Valve | AMOT

Model 4262C air intake shutoff valve stops the engine in an emergency or in the event of engine runaway (overspeed). It can be actuated pneumatically, hydraulically, or electrically and a manual option is available. Features Fast-acting closure Compa

www.amot.com

I converted all of my Detroits to spring actuated racks so I could get rid of the dampers.

 

[Copout911]

Detroit Diesel used to have a shutdown air damper for stuck rack situations due to an injector getting stuck. Perhaps you should consider the same?

4262C Air Shut Off Valve | AMOT

Model 4262C air intake shutoff valve stops the engine in an emergency or in the event of engine runaway (overspeed). It can be actuated pneumatically, hydraulically, or electrically and a manual option is available. Features Fast-acting closure Compa

www.amot.com

I converted all of my Detroits to spring actuated racks so I could get rid of the dampers.

Thanks for the recommendation, I am no more at risk than anyone else now that mine is fixed, but after working on old diesel engines for some time now I was prepared to cut the air with a block off for the intake upon first start.