Anybody ever get into a fuel injection pump that had stuck pistons or other parts? I have an 87 300SDL that I am replacing the pump on, which will not deliver fuel to five of the six injectors. A lot of troubleshooting revealed that the pistons are moving, but that a "rack bar" beside the pistons at the side coverplate would not move with the shutoff lever like the removed pump does.

It looks like it is locked in the shutoff position. Anybody know where to go with this one?

Thanks Big Time!
Gerry

Rebuild the pump. If it got stuck in the 'off' position it might stick in some other position, which could lead to runaway. I've got a IP for a 617 that has a stuck rack, and it was *NOT* in the off position (boy that was fun...).

There might very well be a DIY for this, but I would be very cautious with the pump. I imagine you can find a used one for much cheaper than a rebuild.

__________________
John Robbins
'05 E320 CDI - 240k
'87 300TD - 318k

I talked to Gus Pfister at Pacific Fuel Injection (THE guru on injection pumps!) and he suggested that during shipment, the little roller pins could have come out of their slots on the rack. Sure enough, under the side plate, you can see six blocks with slots screwed to the rack rod. On top of these, there are little valve plates that have roller pins that should ride in the rack slots, but three of mine had come out. Some quick work with needle-nosed pliers popped them back in, and a screwdriver blade pried them down just a bit more so they would not come back out.

It starts and runs!!!

Now I'm tweaking the pump timing just a bit to smooth out the idle, but it is definitely on the mend!

Gerry
87 300SDL