Hi to everyone out there in Mercedes land. I hope this question finds a good home with some w115/ 300d owners out there.

We have a 76' 300d. It has licked its share of peanut butter....... I was told the car itself has over 700K on her. From the condition of everything, I believe it!

We put about 12,000 miles on it with no problems(besides the rust in the tank clogging filters).

This past December it started to have a little trouble starting. Kinda like it was starving for fuel...Finally it reached an impasse. On Christmas eve she said NO.

Fast forward to June the 1st. After testing, proving disproving, adjusting -etc. It seems that there is a Fuel delivery problem in the pump, or the side lift pump. When cranking a ticking can be heard(probably dry inside) There is not one drop of fuel coming out any of the hard lines-no pressure. I can hand pump fuel through the feed/return hoses, but nothing else. The vacuum shut off valve is not stuck or anything of the sort(the rod inside is very free moving). I should say that the filters are not clogged(its running off a clean tank).
My question is, could it be possible that the cam on the lift pump has worn, or broke?
Causing this problem? Everyone I ask about the internals of the IP usually give the same answer(thats not owner serviceable) I have the feeling the people on the other end of the phone are giggling......Its almost like the internals are a closely kept secret, just as the parts are to fix it.

From what I have been told, only a IP pump from a 75-76 will fit this.

Does anyone know if the lift pump from a 77-85 would fit Mr Benz? Ours doesn't have the primer on the lift pump. The bolt pattern, and mounting look identical.

The other problem is getting the ip off the car, those bottom nuts seem to be very pesky! Looks like I may have to take the motor mount-or the whole oil filter assembly off, to allow clearance for the socket