Thanks so much for eveyone's help in this.

A couple of different Mercedes Tech's told me that I need to try to start it for about two minutes straight so that the mechanical pump can get fuel into the system. When I did that the fellow with me found that no fuel had yet gone into the system and the battery more or less died after about 50 seconds.

We hooked up a battery charger that can also provide an additional 200 amps to the starting. We recharged the battery, hooked the 200 amp up, and tried again. After that we even put a couple of quick puffs of ether (diesel start-up in a bottle) onto the air filter so that it could get a boost.

No dice...

We also checked the fuel filter, and that thing is pretty much as tight as a drum at this point.

I know that each of the systems are slightly different (the fuel filter system design we have I believe only applies to the 93-95 models of that generation). ALLDATA says that this is a self-bleeding system and we should just leave it alone for a while. The Mercedes tech's say start it up for two minutes straight.

Next Tuesday we are going to do both. We'll start it up and see if there is any improvement. It could even be low on gas or have some algae problems (it was a repo and probably sat around for a month or two before I got it.) I'm also going to fill it up with more diesel fuel since it only has an 1/8 of a tank left.

Thanks again for all your thoughts and ideas.