1997 Dodge Cummins 12 Valve Bosche injection pump

JDLMODELT

MEMBER
1997 DODGE TRUCK

I have a 1997 Dodge Cummins 12 valve 125k miles, 5 spd, 4x4, with the large Bosche injector pump. It quit running a couple of weeks ago. We replaced the lift pump and check the shutoff solenoid and all were functioning fine. I decided the injection pump was bad since it was dribbling fuel when I cracked the injection lines, but just not enough to make it run. After I removed the pump and inspected it, I noticed a plug on the front of the pump above the input shaft that was about 3 or 4 threads loose. I tightened it, reinstalled the pump and it started. I suspect the timing is now off since the truck will barely idle, has not power and is dumping lots of white smoke. Question is, how do I adjust the alignment between the pump input shaft and the drive gear, since, the pump has a keyway but the gear does not and the two could be mated in any position to each other the entire 360 degrees of rotation. I have worked on aligning several older Roosamaster pumps and they all have the alignment site hole on them. Does this Bosche have a similar sight window for checking timing alignment?
thanks,
James

1 Reply

JOE.KOURY25

MEMBER
1 POST

There are no holes to line up or any keys to time the pump to the motor. The correct way to do it is top have a timing kit with a dial indicator in place of the #1 delivery valve. Although, without this kit you should be able to get the pump close enough. To do this you will have to turn the motor to TDC (top dead center) by turning the motor over by hand, there is a timing pin directly under the fuel pump that you push on while turning the motor over. The pin will fall into a hole in the cam gear. To make sure this is TDC you can pull the #1 valve cover off and both the intake and exhaust valves should be closed.

Now you will have to pull the pump back off and turn it to TDC. To do this you will remove a cap on the right side of the pump (one that is not safety wired) there will be a white plastic plug, pull that out and rotate the pump until you see a little tab that the reverse side of the little white pin will slip right into, (backwards). Now reinstall the pump and DO NOT forget to pull the timing gear back out of the cam gear, and turn the little white plug on the side of the pump back around.