Remove the valve cover and leave the throttle at idle and crank it up make sure you have all the rocker arms moving.....wellll that may be it but it runs good till ya get it wound up... Check the Airfilter make sure its not clogged up they will miss roll the blue and white smoke out if its not getting enough air ,,,,, whene reved up but run fine at lower rpms.. And still could be injectors ,,,,, Had a ford 3000 up here i was working on once , anything above 1500 or more she would dump the fuel thru the exhaust and smoke like crazy.... I went thru the injectors found #2 cylinder was bad that was most of it ,, Stuck new injectors in it , same thing , advanced the timming , wound it up same thing miss smoke and carry on..... swung the battery out and unhooked the thermostart line thought it may be pulling fuel thru it , as i reved it up the rubber hose on the intake from the filter caught my eye as it was sucking shut the more fuel i gave it ,,,,,, cleaned the filter up OIL Bath type ,, put it back togather and the smoke and miss was gone . Might pay to check the air filter....... Watch about pouring oil in the cylinder of a diesel engine with the head on... Very easy to hydro lock the cylinder or get it running off for a few till it burns the oil out , 1 cylinder might not be bad but all 2-4 what ever yours has omg wind up city and pulling the shut down lever wont killit ,, till the oil is burnt up