I don't know what is wrong, but I can't start my 1977 300D for some reason. It is turning over, but the glow plug light does not come one. Well I replaced all of the glow plugs (old filament type), and I replaced the air filter, but my car still won't start. Somebody told me that it is probably going to be something wrong with my fuel system, but I just wanted to get any feedback that anybody might have for me. Thanks