:cI have rebuilt a 5 cylinder diesel engine in my 1981 300D mercedes. The old injection pump, quit. It had over 300.000 miles, so i rebuilt the engine. Now i can not get much fuel to the injectors. I bought a used pump from a car that was alredy running, but slung a rod. Scatched car, sold off parts. I pulled the vaccum shutoff from top of pump, it was not holding vaccum; and puched the stem down manually. It took awhile for rge fuel to finally come through thge injector lins; even now it is weak. Pulled line from injector, held finger over line, and could hold back the fuel. I bled all lies and pump,and filter. Is the pump real weak,or bad, or am i doing something wrong. I shot alittle,i mean alittle either in brather, engine fired for couple seconds. It seems that i not enough pressure to open up the injecdtors. How can i check this. Any help would gladly be appreciated.