911 - I Jinxed Myself - Tractor lost power cutting hay. Want to verify Tec analysis

[RickB]

I'm surprised that any modern tractor has a cam driven lift pump.

A good many do.

 

[SSdoxie]

Fuel flow path is from tank to lift pump to filter then to injection pump. If supply from lift pump is low injection pump will not adequately fill delivery valves to obtain fuel injection volume (good spray).
Remove the hose from tank to lift pump and see if fuel flows steady out of hose. If in doubt blow back through line to tank then release air and see if fuel flow increases. Something may have gotten in tank and obstructing outlet at bottom of the tank. There is no screen at the tank fitting.
If flow form tank seems fine tee a fuel pressure gauge in line going to fuel filter, with engine running pressure should be minimum 3 psi.
Make sure the shut off lever at the filter is in Run position and not partially turned to Air.

 

[SSdoxie]

Its a manual lift pump and issue started with good fuel flow.Nothing electrical we can think of. I changed the filter after the issue and Tec fully bled the system. Fuel is gravity flow as far as I know. but with engine off there was good flow into the fuel bowl and at the lift pump.

There is an electronic sensor located on the lower forward part of the injector pump, but made no difference if unplugged.

Thanks for the thoughts

Its a 2011 m0del . I know there was issues with the Kioti injector pump from around then. Bobcat is a clone of the Kioti. (made by same parent company)

Electric sensor mentioned in the fuel On/Off solenoid. With key on it retracts to allow fuel rack to move. With key Off or wires unplugged it should spring back and shut engine off.

 

[the old grind]

...There is an electronic sensor (??) located on the lower forward part of the injector pump, but made no difference if unplugged..

So that's it, then? If that wire is to the shut-off sol, .. then is there no 12v at the plug with key on, .. or is the solenoid not responding when there is, .. or .. what other wire would go to the injector pump?

(btw so far, my Gs have been WA enough to be proud of .. :laughing

 

[powerscol]

Fuel flow path is from tank to lift pump to filter then to injection pump. If supply from lift pump is low injection pump will not adequately fill delivery valves to obtain fuel injection volume (good spray).
Remove the hose from tank to lift pump and see if fuel flows steady out of hose. If in doubt blow back through line to tank then release air and see if fuel flow increases. Something may have gotten in tank and obstructing outlet at bottom of the tank. There is no screen at the tank fitting.
If flow form tank seems fine tee a fuel pressure gauge in line going to fuel filter, with engine running pressure should be minimum 3 psi.
Make sure the shut off lever at the filter is in Run position and not partially turned to Air.

Thanks
flow from tank was found to be good. Output from lift bump did pulse, but we don't think 3 psi worth. Given lack of spray from fuel in injector lines were guessing lift pump not delivering to injector pump They have ordered parts (lift pump, inject pump, etc so should have tomorrow. They will pick up tractor in Am so if all goes well they will be working on it in the afternoon and possibly get it back to me so I can start hay baling. They have better equipment in the shop than they carry on the service truck. I have asked then to drain and flush the tank while it is there. They know the repair is time critical to get my hay up.

What strange is there is little information here on lift pump failure - more on injector pump issues..

One other symptom - to get it to start now it needs to be a max throttle and let it crank for a long while. You can randomly here it fire until it finally catches. stumbles and runs but only gets to about 2000, etc and sounds like it is missing. Normal is it will catch and run within a second of hitting the starter.

Lastly this tractor has been pretty much problem free for 10 years.

Ill post more as the dealer works on it.

 

[Jabonee]

Lift pump only 3 to 5 psi. check to see if engine is making oil. Injection pump notorious for sticking rack.

 

[Richard]

I'm not familiar with your machine so this might be irrelevant...

I've got an industrial backhoe. Years ago, went through a phase where it simply wouldn't stay running. It would start/idle....once you got underway it would die.

If I let it sit for while, it would again, start/idle.... maybe it would go, maybe it would die.

It totally befuddled me and I went through some of the thoughts you're going through.

Turned out I'd had some water in the tank which got caught in the water separator BUT, it was now literally full of water. So no fuel was getting to machine and when some trickled past the water, it would start/idle....then starve.

Discovered it when I went to check the filter. I was fearing a major repair bill and it was simply the cost of a new filter & the energy to dump a cup of water.

 

[powerscol]

I'm not familiar with your machine so this might be irrelevant...

I've got an industrial backhoe. Years ago, went through a phase where it simply wouldn't stay running. It would start/idle....once you got underway it would die.

If I let it sit for while, it would again, start/idle.... maybe it would go, maybe it would die.

It totally befuddled me and I went through some of the thoughts you're going through.

Turned out I'd had some water in the tank which got caught in the water separator BUT, it was now literally full of water. So no fuel was getting to machine and when some trickled past the water, it would start/idle....then starve.

Discovered it when I went to check the filter. I was fearing a major repair bill and it was simply the cost of a new filter & the energy to dump a cup of water.

When I changed the fuel filter no water found. There was some very fins brown and black residue, call it a smear, in the bottom of bowl (normal for this tractor), otherwise filter looked new. I too have had the water in fuel issues and for me symptoms were different with smoke/white vapor out of the exhaust. Exhaust has been clear, even on the long starts.

Thanks for the thoughts.

 

[powerscol]

Update
Got it back today in time tonight to get 218 bales baled. Neighbor let me borrow his Kubota LS3400 to run my rake this morning. It could not lift it so I had to change up my patterns. It was a manual tractor so a bit of a challenge. Makes me love my hydro that much more.

Anyway it was the injector pump, rack was frozen so that's why the wacky throttle response. They (Bobcat Dealer) have had only 2 of these occur over the years of selling the tractors. I know I should have gotten the old pump, but forgot in the rush to get home and bale. They also changed out the lift pump too. $1700 including delivery. They treated me well on time/parts and delivery. Sounds and runs like a totally different tractor. Much quieter and appears to have more power and much smoother running. Tomorrow to attach the hay grapple and get the bales up before the afternoon showers an so the neighbor can irrigate.

 

[winston1]

Jabonee nailed it post 16. Glad your up and running. Expensive repair. :bawling: