Hello, I own a 1991 300E Mercedes-Benz. I have had it for about a year now. When I first purchased it, I had an issue with the idle being set to low, causing it to run roughly and stall if the RPM's got to low. It ran like a charm until today. I was driving and ended up parked at a red light. Then out of the blue my car began to sound like it was having a very hard time running and then it stalled. It took me 2-3 tries to get it to re-start while sitting there. I had to turn off my headlights and my two ten inch subwoofers and the deck to get it to start. Normally my car begins to sound like its having a rough time running when my car gas tank is close to empty(which it is right now, didn't make it to the gas station nor did I want to try.) I haven't had this issue before and after I managed to make it home, I let my brother take it for a spin. He drove around for about 30 minutes, and nothing, no stalling or anything. I'm worried it may happen again, does anybody know what the issue might be?
I was thinking either the fuel filter, fuel pump, or simply my battery can't handle my subs and new headlights and tail lights I have put on. Any feedback would be helpful! Thank-you.

 

Run some Techron fuel cleaner when you fill your tank. See what happens after that.

 

I had the same prob,same year, replace ovp relay if is the original,check cps for ohms with meter,replace rotor or inspect and clean,check rotor mount, mine had a crack in it,replace plugs,wires , dist cap, lots of things can cause the problem,but after I did all that no more stalling 400 miles later,also check duty cycle,search out threads lots off them on this problem with these cars
Luck John!

 

Thanks! I'll try these and see if it works.