Recently, I purchased a 1990 240DL w/215K plus, and for approximately 1 month,it ran just fine. Not knowing the maintenance Hx, I had the timing belt changed. About two weeks afterward, the car started spitting, sputtering and would stall. Sometimes it would not start back up. I initially thought it was a fuel system problem( filter, pump or something else). Took it back to my mechanic and he thought the problem was the air mass meter. Rplcd and problem continued. Car is getting plenty of fuel to injectors even flooding plugs. Problem happens whether its warm or cold outside and a couple of times, quite a bit of carbon came out of tail pipe when it did start. Any suggestions from anyone with similar problems? I'm stumped!