History. Replaced DE Standadyne pump June 2016. Dozer ran fine. Has 5000 hours. Recently started to blow white smoke at 2350 RPM and RPM drops below 2000 and runs rough. Move throttle down to 900 and runs smooth. Back up t0 2350 and it will bog down under load. Pulled injectors and had JD bench test. One was junk and the others barely passed so we replaced all four. Still blows white smoke. I am thinking it could be a timing issue so I checked it and it was good. What controls the advance for pump when under load?
An internal transfer pump raises & lowers the internal pressure to control timing advance.. driven off the pumps drive shaft. The transfer pump blades wear out ALL THE TIME.. Its found by taking a TP reading on the test stand w/ a pressure gauge. Its screwed into the double screw on the side of the pump.. @ x rpms you should have X psi.. and its adjustable.. BUT, if your TP pressure is so low its retarding the timing, its in need of replacement and not an adjustment. It could also be a broken accumulator spring inside the pump.. happens all the time & will give the same symptoms.. IF its an accum. spring.. get the pump/engine skipping/missing and hold it there.. now break an injector line loose and see if your getting a ton of air.. if so, its the accum. spring & the pump has to come apart.. IF your feeling adventurous.. remove the torx screw from the side and rig up an adaptor & a 200psi gauge and I'll tell you what the pressure is supposed to be..