Z750 Injection Pump

[Viva-la-L175]

Hey guys,
I'm finally starting down what will probably be a years long road of restoring my grandfather's L175 to 1973 condition-- which will probably lead to a lot more questions as I go. Today my question is about the injection pump. Whenever you are working the tractor hard and suddenly let off the throttle for some reason, it wants to die. You always have to throttle down pretty slow on it. It wasn't always that way, but this is an issue that has developed over the years. My suspicion is that the injection pump is getting worn out. I see that a replacement that I would trust is pretty pricey but I would do it if there was no other choice. My question is... Do you all think my suspicions are correct and if so, how hard would it be to rebuild the pump? Also, I haven't found any rebuild kits just for it online but I may not have looked hard enough yet. Thanks!

 

[JerryMT]

Hey guys,
I'm finally starting down what will probably be a years long road of restoring my grandfather's L175 to 1973 condition-- which will probably lead to a lot more questions as I go. Today my question is about the injection pump. Whenever you are working the tractor hard and suddenly let off the throttle for some reason, it wants to die. You always have to throttle down pretty slow on it. It wasn't always that way, but this is an issue that has developed over the years. My suspicion is that the injection pump is getting worn out. I see that a replacement that I would trust is pretty pricey but I would do it if there was no other choice. My question is... Do you all think my suspicions are correct and if so, how hard would it be to rebuild the pump? Also, I haven't found any rebuild kits just for it online but I may not have looked hard enough yet. Thanks!

Never heard of this before. When you cut back on the fuel, the engine should return to idle. I wonder if you idle setting is too low? If so, that's easy to correct by turn the idle screw against it's stop to increase the idle speed. The pumpguy, another poster on this forum, may have a better answer for you but don't start fiddling with the IP until you've ruled out other simpler possibilities. How many hours on your machine?

 

[North Idaho Wolfman]

I would look at replacing the Injectors before you go down the dark path of the injection pump.

 

[Viva-la-L175]

Never heard of this before. When you cut back on the fuel, the engine should return to idle. I wonder if you idle setting is too low? If so, that's easy to correct by turn the idle screw against it's stop to increase the idle speed. The pumpguy, another poster on this forum, may have a better answer for you but don't start fiddling with the IP until you've ruled out other simpler possibilities. How many hours on your machine?

It's possible the idle is set too low. There was an intermediate owner before I bought it back and he maintained it but wasn't big on what I would consider proper repairs. The tach cable was gone when I got it back from him but I'd say it has somewhere between 2000 & 2500 hours on it. All engine parts are still original.