Fuel Injection Timing - Mitsubishi 4DQ50 Service Manual

3) When injection pump needs to be removed for adjustment or servicing,
try
to
learn how to set it right again, memorizing especially in what relation the
match mark on injection pump flange part is to the mark on the flange plate.
(Refer to Fig. 3-22) Before it is fixed again, never run the engine lest the
injection timing should go wrong. For removing, take the follwoing steps.
Loosen clamp bolts that fasten pump flange to engine crankcase with a socket
wrench fitted on the end of universal joint. Then, unfasten cover from timing
gear case and separate injection pump gear from pump camshaft. To leave the
gear in mesh with idler in gear case will make the pump setting much easier
don't c!isjoin autotimer from the gear, for easier operation in installment.
Having removed injection pump, put caps on delivery valve holders to keep off
dust.
4-5 Fuel injection timing
In this engine, injection pump starts injection at a fixed time, whatever the
injection rate may be. Model 40Q50 is attached a mechanical autotimer in option,
which is coupled with injection pump gear, varies the injection starting time according
as the engine speed changes and thus provides always the fittest injection timing. This
injection pump is fastened by means of flange so that injection starting time can be
varied by changing its setting angle. The pump having been adjusted right to the values
and firmly fixed at our factory, the injection starting timing will never to wrong.
Fig. 3·21 Timing mark on crank
shaft pulley
- 27-
Fig. 3·22 TIming mark on flywheel