I have a 1985 500sel and when i start it, the engine turns and turns but it won't fully turn on. then i take off the post on the battery so the engine shuts off. if i come back to the car in a while then try too start it , it turns on ok. But recently it started doing same thing the engine turns and turns when i start car. some one said it might be the fuel filter relay. would someone please help me! I very much would appricate the help.[;)]