Engine Performance problem
1986 Mercedes Benz 300e 6 cyl Two Wheel Drive Automatic

i have a 1986 mercedes benz, 300e, and every time i crank up in the morning i have to hold the gas pedal to the floor for about four or five minutes. the starter spends over until it finally cranks about five minutes later. i use to have to pour gas in the coperator in order for it to crank, but now i just hold the gas pedal to the floor. Do anyone have a solution