4230 Injection Pump

[greenmachine]

Tractor has a random miss that usually comes when it gets used for an hour or so. I can crack the injector lines and it will get a hard miss on cylinder. Injector are new,engine is completely rebuilt, head was redone new valve guides, seats etc. I checked valve height, intake/exhaust are spot on according to factory specs.Timing of the pump is dead on, valves are adjusted correctly. Pump was rebuild many years ago,is it possible it is pump related? I am about out of ideas. Tractor will smoke lightly at idle when it is missing.. Almost like it has to much fuel, doesnt make sense to me.. Not sure where to look next. Thanks!

 

[Tx Jim]

Even though you stated new injectors I'd guess injector problem.

 

[PSU4250]

I would say it is probably a pump issue with the advance piston. They were known for the advance piston bore getting scorn and having the piston stick. The fix was an updated housing, I believe with a stainless insert and new advance piston.

 

[greenmachine]

My gut was thinking that as well,new doesnt mean
anything I guess. I can crack each injector and it
will really miss. Was hoping I could pin point it by
doing that, but they all respond the same. Only
other possibility is something is stuck in one of
the injector lines, I could take them each off, blow
them out.. Ran great for 2 hrs this morning, wont
stop missing now.. Have to let it sit overnight and
see what happens.

 

[Anonymous-0]

Did engine do this partial miss before overhaul? I found an injector loose on my engine-tightened it(depends on year of tractor-takes a 3/4 tube wrench for mine-a later model one) and it is firing on all six now. Injector could have went south also. Have injector verified that it is good-probably your pump if injector is good.

 

[Tx Jim]

I would suggest to pressure test the injectors.

 

[greenmachine]

No it didnt, new motor has 100 hours on it now, just started in the last 6-8 hours.

 

[Anonymous-0]

If something was in the line, it would go to the injector. If it was the pump it would have been missing before.
If injectors check out it could be a valve not seating properly even though they have been done.
I would take the manifolds off and roll the engine over slowly by hand. You can hear compression leakage and that cylinder won't have that pop when the ex valve opens as the others do.
Someone on here had that problem a while back as did I. Valve shop had a lot of trouble gettin it to seat properly.