Can someone help me solve a rough running 300sel problem. To me it looks like an elect. glitch somewhere. Car runs ok on idle (misses just a bit) but when stepping on gas it gets progressively worst to the point that engine won't spin over 3000rpm (backfires, coughs .....). Brand new spark plugs, wires, distributor and rotor plus lambda sensor installed. It helped some but not much. Using M-B, I checked ignition system: timing is ok with cold and warm engine, dwell angle looks to be ok (30), vacuum advances ign. as req., ign. coil seems to be ok. One thing I noticed during timing check with timing light was that as engine was missing timing light was skipping/missing too. As rpm were approaching 3000 engine was stumbling and timing light was "to". Is this a bad coil or ignition module? Also there
is a lot of black sod coming out from exhaust pipes.
Thanks in advance for any help.
89 300sel 200K