I have a 1991 Mercedes 300E that I have spent $2000 in repairs in the last year. I have replaced the cold start valve, time switch, EGR Valve, O2 Sensor, Fuel Distrubutor, Rotor Button, Distibuter Cap, Plug wires and plugs. None of this helped my starting problem. For months I had a hard time starting the vehicle even after replacing all this. The car would turn over and after trying 3 times would start and suddenly cut out, then would restart fine, But you cold smell gas in the tail pipe. Finally the car stopped starting and when it does start it sounds awful and idles very low then when you touch the gas it cuts out and is undrivable. Whwn you turn the switch you can hear the fuel pump come on, but it does not seem like it is getting gas to start. Could this be my Fuel Pressure Regulator?