You dont say what injection pump you have on your major, if it is one of the diaphragm type have a look at the diaphragm and make sure its in good order, also check the suction and bleed pipe's, there are the ones coming from the pump to the inlet manifold, check also the idle speed it should be 540-560 RPM. if the engine surges at idle speed or at a slow engine speed at whick the engine must run for certain operations, loosen lock nut and slowly turn damping valve quide adjuster back and forth to find positon that wil most effectively reduce surge.
Tony, May 2010
