I am having trouble with my 96 E300 Diesel with the security system not letting me start the car and then for no reason shutting it off in midstream. I can usually wait for a coulple of minutes and then it will restart but it is still kind of scary not knowing just when it will happen. The 2 lights in the rearview mirror will flash red and green and then its no go any help will be appreciated.

For the “No Start” condition I believe the pickup coil surrounding the ignition lock would be a good place to start, this may cure your intermittent starting problem (mirror lights flashing).

If the vehicle is dieing while driving try having all the semi-clear fuel lines connected to the injection pump replaced. You may want to also double check the pre-filter o-ring. A new pre-filter does not come with a new o-ring so the old one often gets reused. All of these fuel connections can be a source of unwanted air in your fuel system.

My approach is to eliminate the known problems............proceeding further if needed.