While driving down the road at 40mph, the engine just died. When I try to start it, it sounds as if it's not getting enough fuel(it tries to start). Should I start with replacing the fuel filter?

Try and listen to see if the fuel pump is working. If it isn't, investigate the relay, check for power at the fuel pump. You can see if it will run with some starting fluid sprayed into the intake. If it will run for a couple of seconds it is probably a fuel proplem. If it still will not start the check the ignition system.

I would have to look at the over-voltage control unit or the ignition switch. I have had both fail.

96 E300D
 

Thanks to all for replies,
It eventually started by periodically cranking it but I noticed "bubbles" in the fuel line coming from the filter. I replaced the filters and so far no problems(only 5 mi.) I'll let you know.
happymat

you may need to bleed the fuel system good , ..air in the fuel oil is not conducive for proper operation.

Rudy,
As far as I know, this system is a "self-bleeding" system, if you know any thing different, let me know.
Thanks,
Matt

I forgot to add that there were no visible "bubbles" in the lines after I replaced the filters.
Matt