i have a customer with a case 1845c. i have trouble getting full throttle out of it. i have adjusted the throttle stops but no help. evey now and then it will go to full throttle. i'm suspecting the injection pump. it has new fuel filters and air filters. i did check lift pump pressure and i was getting around 6psi running at full throttle.
Sounds to me that the mechanical centrifugal governor is hanging up inside the pump. This can be a typical problem as the linkages and pins wear inside the pump over time. Do you know many hours on the unit?
assuming its still the original motor and hasn't been rebuilt its around 12,500hrs.
That is getting up there for sure. Hate to tell you to get the pump rebuilt because that too can get expensive but it sure sounds like the problem to me. With throttle linkage off the pump can you move the pump shaft through the full range from low to high idle by hand? Try this with engine running to eliminate a mechanical linkage from the cab hanging up. Sometimes that will happen.
yeah i've tried that. once i did all my previos testing i was pretty certain the pump is to blame
Any smoke when your at high idle? You don't have a bad or slobbering injection adding to the lack of high idle?
no not really it seams to burn pretty clean. it runs good and smooth at idle or full
Off the top of my head I don't know what else to suggest. Let me know what you find when you get the pump apart.
Depending on the year it may have a CAV pump they are relatively easy to repair and not extremely expensive.