7275 injection pump question

[jccuth]

Hi,
I have a 7275 cub cadet tractor that reved high and the key would not shut the tractor down. I had to turn off the fuel supply at the settlement bowl to shut it down. I did not run out of fuel. I cleaned the fuel filter and I bled the lines and have fuel going into the injector pump but don`t have any coming out of the 3 lines going to the injectors. Any thoughts on my next steps to try? If I end up pulling the injection pump do I have to first remove the govoner?

 

[Muhammad]

Welcome to TBN.

 

[jccuth]

Thanks Muhammad, This looks like a very good site where I`ll be able to learn a lot.

 

[kensnelling]

Welcome to the forum from Oklahoma.

Ken

 

[jccuth]

Thanks Ken

 

[Cub 7274]

My 7274 died on me- shut it down then would not start
I had to have the injection pump rebuilt as the fuel was not going past the pump to the injectors
There are "shims" that control the timing I believe
I had it done by a business and the cost was $1700 to remove repair replace
Runs fine now

 

[moored4]

:welcome: to TBN! :thumbsup:

Happy :tractor: ing!

 

[jccuth]

Cub7274
It may be the pump broken, but I took the inspection plate off and the 3 injector ports off the top of the pump and found no obvious broken parts or pluged injectors so I`m thinking it may be the selonoid on the front of the injector pump. I ordered a new one it cost about $150 dollars so I hope I`m right. It said it would be at my place between the 19th and the 23rd. Thanks for your responce and help. I`ll let you know if the selonoid solves the problem. I read that if the selonoid is bad the valve will not open thus keeping diesel fuel to be pumped out the pump into the injectors.

 

[creekbend]

Welcome aboard. Best wishes.

 

[jccuth]

Thanks Creekbend

 

[Cub 7274]

I hope you are correct they thought mine was the fuel shut off solenoid initially but it was working fine so hopefully you will get away cheaply good luck

 

[DieselMonk]

The pump may be air locked. There should be a "bleeder skrew" on the pump somewhere. It should be mentioned in your owners manual. It should be somewhere on the top (as air rises). As I recall, you have to give it full throttle, while engine is NOT running. make sure the fuel is turned on, then crack the line right before the injector pump until no more bubbles come out. Then you open up the injector pump bleeder screw and do the same. If it still doesn't start, crack the injector lines at the injector, one by one.

 

[jccuth]

Thanks DieselMonk for the information. I think I have bled everything. There is bleed screw on top of the sediment bulb than as you follow the fuel line there is a bleed screw on top of the injector pump. I bled both of those points getting the air out. When I cracked the lines that exit the injector pump and crank the engine I get no fuel. The thing you said I may have done wrong was to crack one at a time. I`m not sure if I did one at a time or all 3 at the same time. I`m going to go back and re-bleed the lines and make sure I only crack one line out the injector at a time.
There is an inspection plate on the side of the pump and one on the side of the govoner. It allows me to see the pin on the selonoid moving back and forth. I can also see a wheel similar to a saw blade with out teeth in the govoner. It turns and there are 3 or 4 small blocks with a groove or hinge point that evidently cause the selonoid pin to move in and out. Anyway I am not a mechanic but I see no mechanical problem. I`m not certain where the valve is that opens and shuts allowing fuel out the injector pump. I believe it runs off a small intermitten electric charge from the selonoid.
I`m going to try bleeding the lines one more time to make sure I did it right.
I really like this tractor and have been working her hard. I have about 25 acres that has not been farmed in a couple years. I was plowing with a 2 bottom plow. I hope I get it figured out pretty soon even though I won`t plant beans until about the 1st. of May.
Thanks

 

[Cub 7274]

The solenoid pushes a rail of some kind that allows fuel to flow into the pump. When you shut the key off the solenoid pulls back and the rail slides and fuel flow is stopped my problem was beyond that "rail"

 

[jccuth]

Now I`m not sure any more. When I watch the selonoid pin when I crank the tractor its moving in and out although when I was cranking the tractor the selonoid seemed to get hot when I touched it. I also saw when I shut the key off the selonoid pin pulled back.

 

[Cub 7274]

I dont think the solenoid should be pulsing it pushes the rail in when you turn the key on.
If its pulsing I think you have a problem and thats why its heating up
Time will tell when you put the new one in

 

[jccuth]

Great News!!!
I took the injector pump out of my tractor and bought it in the house to disassemble and clean. I learned that the valve that sends fuel out of the injector pump was sticking thats probably why the selonoid pin appeared to pulse because it could not push the pin that opens the valve up. I cleaned it good and lubed it with WD40. That must have been the problem. I put the tractor back together and found it now pumps fuel out the injector pump. When I tightened the lines it fired right up. I`m going to make sure I change the fuel filter on a regular basis. This problem taught me what a little dirt in the fuel can do.
Thanks for all the comments they really helped.

 

[Cub 7274]

Well done

 

[7275]

I just had this happen to me and it did exactly the same thing and it is a jammed injector pump. $1293.00 for a new pump not including labor. Joys of owning a deisel tractor. 900 hrs when it happened to me. I am going to send it out to D&W injector service and see if it can be rebuilt.

 

[Short Game]

The solenoid is for shutting off the fuel, not opening up the individual injector pumps' fuel meters. The loud clack when you shut off your key is the solenoid releasing its plunger to slam forward and block the governor from increasing the fuel supply. When you turn on the key, it pulls away from the rack gear that the governor pushes aft to increase the fuel through the three injector pump pistons.

I had an issue that could have been this same one with my 7274. In my opinion, that shutoff solenoid has too powerful of a return spring, and it slams that rack gear forward too hard when you shut off the key, and it can break a tooth off one of the three pinions, and that broken tooth can get stick in between the rack gear and the broken pinion. That rack gear rotates the metering rods in the three pumps via the three pinions.

I was able to take my pump apart and find the broken pinion. Being careful to not mix the parts from the three pumps, I replaced the broken pinion, which I got through a fuel injection specialty shop in Portland, OR. The pinion cost $7 and saved me the $1300 that I had found a pump selling for online.

With the broken tooth gotten out of the way, you could have only two of the pumps working at full capacity. The pinion with the missing tooth would only rotate the metering rod so far. The tractor would run again, but one cylinder could possibly be running lean. Mine would not run at all when the broken tooth was jamming the rack gear.

Though the guy at the fuel injection shop had never heard of this problem, I still live in fear of it happening again, every time I shut off the key and hear that loud clack!

All I did wrong was to turn off my key. It took me weeks with my tractor dead in my neighbor's front yard, cranking the engine for hours on end, and all my diesel expert friends standing there and scratching their heads along with me. It was not easy to work on with the loader in the way.

I know I'm late with this, but it might help someone else.