300E Sportline Edition Stalling

I'm been having some problem with my 1993 300E Sportline. From time to time it stalls on me when ever I'm about to stop or sometimes in idle. the engine just suddenly dies on me, sometimes I don't even know that it stalled already. and when you try to start it wouldn't. you have to wait from 1 to 5 minutes before it would start again with no problem. I brought it to the dealership and they told me that the electronic engine actuator is malfunctioning. so i had the mechanic change it and the relays that are burned out. After all those expenses and work it still stalls on me. I've going back and forth to the shop for the last 3 weeks. Does anybody have a solution or even an Idea what's wrong with my Car? Any help would be greatly appreciated, I'm really getting frustrated and sometimes I'm in the middle of an intersection when it decides to die on me.