Hi john, I would advise taking the cover off on the timing gear cover in front of the pump, get someone to help spin engine over while looking in, you should see a punch mark on the idler gear and the injector pump, they can take along time to acually meet up,then pull the IP and replace with the marks meeting,another way of doing it also is to unbolt the IP off the IP timing gear. Mark for tooth alignment and leave as is remove battery leads so no one trys to start it! I have done it this way with no problems, I posted a video on youtube on the timing gear alignment on my six cylinder engine,very much the same as your 4000 engine if you get stuck,cheers