773 injection pump troubleshooting

[firebird_1995]

im pretty sure mine is shot. the engine is hard to start, but once it starts it runs good. i took the injectors out and checked the spray pattern by hooking them back to the pump and cranking the engine over and all 4 injectors are good but im only getting good enough pressure to crack the injectors on the #4 line. i took the pump off and the fuel cam looks ok. does this sound like a bad pump? the fuel system is full of crud due to the pickup screen in the tank being broke but i would have thought the filter would have caught the majority of it. id like to disassemble the injection pump to check for anything hung up/plugged before i replace it. has anyone ever done this before? any tips?

 

[firebird_1995]

also, when i had the injectors off the lines, while squeezing the primer bulb, the #3 line has a steady stream of fuel coming out. seems like the delivery valve might be stuck open on that cylinder.

 

[Bobcatdan]

also, when i had the injectors off the lines, while squeezing the primer bulb, the #3 line has a steady stream of fuel coming out. seems like the delivery valve might be stuck open on that cylinder.

Normally kubotas don't have injector or pump problems. Starting hard like what you are talking about is normally low comression on 2 and 3 cylinders, or a cracked head. As a bobcat dealer, we do nothing with injections, they have to go to a cert. diesel shop. My manuals do not cover the pumps and I can't get very many parts. What I am saying is take the pump to get checked out. Also have them test the injectors. If crap ran threw them they could be damaged, but the filter should have plugged up long ago There are EPA laws restriction who can work on pumps due to emmissions.

 

[firebird_1995]

Normally kubotas don't have injector or pump problems. Starting hard like what you are talking about is normally low comression on 2 and 3 cylinders, or a cracked head. As a bobcat dealer, we do nothing with injections, they have to go to a cert. diesel shop. My manuals do not cover the pumps and I can't get very many parts. What I am saying is take the pump to get checked out. Also have them test the injectors. If crap ran threw them they could be damaged, but the filter should have plugged up long ago There are EPA laws restriction who can work on pumps due to emmissions.

I took the injectors and delivery valves on the injection pump apart and cleaned them. rechecked for spray and it checked out good! Put it back together and it fires up on the first hit now! It sat for a few years with fuel in the lines so it was gummed up pretty good.