L785 kills when throttled up

[buchholtzj]

My L785 (Ford Diesel) starts and idles fine, but when I throttle it up it will run fine for a little while then will kill unless I throttle it back down to idle. I removed the water/sediment separator, cleaned it (there was some gunk in the bottom) and replaced the rubber seals and replaced the fuel filter. After doing so, I have also bled the air out of the fuel system at least a dozen times. It will idle all day and no air in the system, but every time after it "almost" kills, there is air back in the system. Any thoughts would be greatly appreciated, thanks.

 

[deaop06]

I would check all the rubber fuel lines for cracks or a hole. Sounds like the air is getting in while under a load. Increase demand for fuel is when you have the problem. Check the hose clamps that they are not loose. That is where I would start. Good luck

 

[buchholtzj]

I would check all the rubber fuel lines for cracks or a hole. Sounds like the air is getting in while under a load. Increase demand for fuel is when you have the problem. Check the hose clamps that they are not loose. That is where I would start. Good luck

Thank you very much for your response! I'm heading out there this morning and will check check everything you mentioned. If I don't find anything there I think I will check for any restrictions in the fuel lines or tank. I bought the skid steer 3 months ago and it ran great those 3 months, but it sat for almost 4 years before I bought it. I've read in other posts the algae can grow in the fuel tank, maybe something just now got jostled loose and is restricting flow. It's just a thought, but maybe when it's idling it gets enough fuel, hence no air in the system, but when I throttle it up, it pumps/sucks harder but can't get the fuel, but pumps hard enough to suck air into the system..??

 

[deaop06]

Thank you very much for your response! I'm heading out there this morning and will check check everything you mentioned. If I don't find anything there I think I will check for any restrictions in the fuel lines or tank. I bought the skid steer 3 months ago and it ran great those 3 months, but it sat for almost 4 years before I bought it. I've read in other posts the algae can grow in the fuel tank, maybe something just now got jostled loose and is restricting flow. It's just a thought, but maybe when it's idling it gets enough fuel, hence no air in the system, but when I throttle it up, it pumps/sucks harder but can't get the fuel, but pumps hard enough to suck air into the system..??

My machine sat for 6 years. Not much fuel when we got it. I added 5 gals with some PowerService clear diesel to tank. So far I have not had any problems with the fuel. I will use more as I need fuel. There is enough in bottle to treat 100 gals. Good luck on finding your air problem.

 

[buchholtzj]

My machine sat for 6 years. Not much fuel when we got it. I added 5 gals with some PowerService clear diesel to tank. So far I have not had any problems with the fuel. I will use more as I need fuel. There is enough in bottle to treat 100 gals. Good luck on finding your air problem.

I believe I have isolated the problem! I wanted to figure out if it was something restricting flow from the tank or if it was an issue with the pump or injectors, so I disconnected the fuel supply line where it goes into the sediment and water separator and put a 3' piece of brand new fuel line and ran that into a separate 5 gal. can of fresh fuel. It ran perfect throttled up at working RPM's. Now I'll pull out the suction tube in the tank to inspect/clean that then try and pump out as much of whatever crap and sludge is at the bottom of the tank with a transfer pump. deaop06, I was actually in the fuel additive isle at the local Farm & Fleet store when I received an email about your reply to my post, so I picked up a jug of Power Service Clear Diesel and will also add some of that to the tank once I'm done cleaning and flushing it. Long as I'm in there, I'll probably replace the supply and return fuel lines too. Thanks for your reply!

 

[Erik6693]

I believe I have isolated the problem! I wanted to figure out if it was something restricting flow from the tank or if it was an issue with the pump or injectors, so I disconnected the fuel supply line where it goes into the sediment and water separator and put a 3' piece of brand new fuel line and ran that into a separate 5 gal. can of fresh fuel. It ran perfect throttled up at working RPM's. Now I'll pull out the suction tube in the tank to inspect/clean that then try and pump out as much of whatever crap and sludge is at the bottom of the tank with a transfer pump. deaop06, I was actually in the fuel additive isle at the local Farm & Fleet store when I received an email about your reply to my post, so I picked up a jug of Power Service Clear Diesel and will also add some of that to the tank once I'm done cleaning and flushing it. Long as I'm in there, I'll probably replace the supply and return fuel lines too. Thanks for your reply!

Hello, I just picked up my first skid steer it's an 1985 l785. So far I love it but don't know to much about it, you don't happen to have a service manual you would be willing to share would you? Also overall how do you like yours? Thanks

 

[deaop06]

Hello, I just picked up my first skid steer it's an 1985 l785. So far I love it but don't know to much about it, you don't happen to have a service manual you would be willing to share would you? Also overall how do you like yours? Thanks

Erik6693 www.jensales.com has them. They are $40 each. You should have the service manual and a parts manual. You may be able to pick them up cheaper by surfing the web. The owners manual tells you how to adjust and service the machine. I know they are a lot of money but will pay for themselves over time. Good luck on your new machine.

 

[Ivan]

I believe I have isolated the problem! I wanted to figure out if it was something restricting flow from the tank or if it was an issue with the pump or injectors, so I disconnected the fuel supply line where it goes into the sediment and water separator and put a 3' piece of brand new fuel line and ran that into a separate 5 gal. can of fresh fuel. It ran perfect throttled up at working RPM's. Now I'll pull out the suction tube in the tank to inspect/clean that then try and pump out as much of whatever crap and sludge is at the bottom of the tank with a transfer pump. deaop06, I was actually in the fuel additive isle at the local Farm & Fleet store when I received an email about your reply to my post, so I picked up a jug of Power Service Clear Diesel and will also add some of that to the tank once I'm done cleaning and flushing it. Long as I'm in there, I'll probably replace the supply and return fuel lines too. Thanks for your reply!

If it happens again take your new line off and check it for some brown gunk in it. If there is any get some biocide and treat the fuel in your tank for alage.