7775 No fuel to injectors

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n.dangelo2024

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Jan 8, 2024
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Hey guys,
I have a 7775 skid steer and it won't fire. Did some trouble shooting already: Fresh fuel, fuel solenoid pulls in when cranking and stays in once you stop cranking, releases when key switched off. Got clean fuel coming back through return line from filter housing.
Cracked the injector lines and crank machine, no fuel coming out.

Any suggestions before I pull the injector pump out?

Thanks
Nick
 

foton

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Mar 1, 2018
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1,300
know nothing about that machine but most have a manual fuel pump to like prime the system after a fuel filter change look for that and check fuel being there or not and any rubber fuel lines for holes or cracks causing a vacuum leak so pumps can not pull fuel up.
 

jkwalmer

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Mar 14, 2024
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Greetings, any update. I am working on a similar unit. 1994 JD 7775.....same issues. Same results. Trying to diagnose before removing Fuel Injector Pump......thank you...jack
 
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n.dangelo2024

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Jan 8, 2024
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Greetings, any update. I am working on a similar unit. 1994 JD 7775.....same issues. Same results. Trying to diagnose before removing Fuel Injector Pump......thank you...jack
I ended up replacing the injector pump, was an easy swap, fired right up after that.
 

jkwalmer

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Mar 14, 2024
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Ok...good to know. I am waiting for a replacement fuel pump to see if it corrects non-start. Fuel shutoff solenoid operates. I am looking for any videos on replacing the Injector pump. What issues if any, did you run into when swapping out the injector pump? The technical Manual does not provide alot of help.
 

jkwalmer

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Mar 14, 2024
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Greetings again, one big question would be if you had to remove the radiator and hydraulic cooler to access the drive gear?
 

jkwalmer

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Mar 14, 2024
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I ended up replacing the injector pump, was an easy swap, fired right up after that.
Ok...good to know. I am waiting for a replacement fuel pump to see if it corrects non-start. Fuel shutoff solenoid operates. I am looking for any videos on replacing the Injector pump. What issues if any, did you run into when swapping out the injector pump? The technical Manual does not provide alot of help. Did you end up removing the radiator and hydraulic cooler?
 
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n.dangelo2024

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Greetings again, one big question would be if you had to remove the radiator and hydraulic cooler to access the drive gear?
Did not remove the radiator, you can remove the gear cover and there is just enough room to get a socket in and remove the one not holding the gear on. There is a timing dot on the gear, make sure you note the position before you remove it as it will have to go back in the same orientation. Also the three bolts that hold the injector pump in are clotted so you can make slight timing adjustments by turning the pump one way or the other. I make a mark on the pump and the bell housing and just lined those marks up when i put the new pump in.

Hardest part is getting the rear mounting nut off, its tight between the pump and block.

Good luck!
 

jkwalmer

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Mar 14, 2024
Messages
7
Did not remove the radiator, you can remove the gear cover and there is just enough room to get a socket in and remove the one not holding the gear on. There is a timing dot on the gear, make sure you note the position before you remove it as it will have to go back in the same orientation. Also the three bolts that hold the injector pump in are clotted so you can make slight timing adjustments by turning the pump one way or the other. I make a mark on the pump and the bell housing and just lined those marks up when i put the new pump in.

Hardest part is getting the rear mounting nut off, its tight between the pump and block.

Good luck!
Ok. Thank you for the info very helpful.....jack
 

jkwalmer

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Mar 14, 2024
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Greetings again, Sorry to be a pain. Couple more questions....How did you see inside the bell housing without removing the radiator and hydraulic cooler to line up marks on gear? Also what wrench and adapter did you use to get the inside bolt off. Did you go down from the top?
 

jkwalmer

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Mar 14, 2024
Messages
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Greetings, thank you again for your assistance. Just to give you an update. I am taking a Small Diesel Engine Repair Class at local Community College. We went over fuel injection pumps last week. The education was timely and priceless. My last effort before swapping out pump was to remove the lines and top end of each piston. I had to ensure keeping all the pieces in line and in order. The pistons were froze due to not running for so long. I sprayed generating oil in each. Lightly tapped on piston with brass punch. Cycled unit to ensure each piston stayed free. I had to do this numerous times until all remained free. Put everything back together. Bled lines and unit fired up......luckily I didn't have to replace pump ...thank you again
 
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