What would cause my 92 Mercedes Benz 300E to start and cut off need advice plz

Great. Start by testing the fuel pressure at the throttle body. If it starts with an aerosol, it is not getting fuel. If you don't have the tools needed, a quick test is to turn the key to the "ON/RUN" position, and listen for the fuel pump to run in the rear of the vehicle. If you do not hear it, test the connector for power (you can use a 3 dollar test light for this). If it has power but does not run when the ignition is on, it is bad. Since it has been sitting for so long, you should change the fuel filter as well, since anything that built up in the gas tank (rust, sediment) is now in the fuel filter. If this seems like a daunting task, there are certified shops nearby to help you out with diagnosis or repair. Just click the link to find one. http://repairpal.com/mercedes-benz-within-10-miles-of-san-marcos-texas-78666