I recently changed oil and all filters on our engine. Was not able to get all the air out of the system and so put a ball pump on the fuel line, and thought I had all the air out. But when we ran the engine we could still not get full power. Seems to run fine up to about 3/4 throttle, but then get no more power with the last quarter. Can't think of what I missed, unless there is something between the fuel injector and fuel pump. Would appreciate any tips as this is our second year with the engine and I have had little experience with deisel engines.