Mario,

I don't think your car has an electric fuel pump. I think you just keep cranking until it starts. It will take a long time if you didn't put fuel in the big filter before installing it. I think I've read that it can take up to a minute of cranking. Check the archives because that seems like a good way to burn the starter.

On my 603 engine, I loosen the fittings at the injectors and tighten them as fuel spills while cranking. Doing it this way, I crank it for 10 seconds at a time and for no more than 4 times before it runs on its own.

My small filter fill up with a few seconds of cranking so it's easy to see that fuel is flowing.

FWIW, I replaced the filters in my 617 last week and I didn't even have to prime at all. Just filled the big filter with Diesel Purge, crank and start.

Sixto
91 300SE
87 300SDL
83 300SD