99 E300D - Fuel filter change = No Start

[George301]

1999 E300 Diesel W210 - Help!

The story so far . . . The car was starting to get sluggish under acceleration, so I decided to change the fuel filters. I changed the pre filter and after some cranking it came to life fine. Then I changed the main filter and it will not start at all, after a tremendous amount of cranking. After a few minutes of cranking is coughed but that has been it. I have changed the filters before and know it takes a mess ‘o’ cranking to get the air out. I have about a third of a tank and have jacked up the rear to try to encourage fuel flow.

I used my hand vac pump to make sure fuel was getting to the engine compartment and then thru the filters. I got flow at both places so it seems the lines and filter are o.k. I was also able to blow air thru the return line. I then cracked the nut where the first injector enters the engine and nothing came out while cranking.

Important bit -
My next experiment was to put the line from the lift pump straight into a cup of diesel, much cranking and still nada. This does not seem good, but all I did was change the fuel filter.

Diagnostics are just not my area of expertise but could the fuel pump be shot, even though I only messed with the filter??

Thanks for any help!
george