I do a lot of diagnosis on cars, and have a friend with a 1991 560 sel.
Cylinder #1 refuses to run for 3 years now. All ignition parts are new.
Engine was rebuild 3 years ago.
Injectors are new, so is the fuel distributor. Compression is OK.

I have seen issues with camshafts, and cylinder #1 is suspect for lack of lubrication.
Apparently the engine had this miss even before rebuild.
Cams were not replaced, soo.. Is there a likely hood of a cam problem?
No valve noises at all.
Spark plug on #1 show signs of running much richer, than the other 7.
Injector and fuel distributor swap result in no change.
The miss is consistent, it stays even at higher RPM's.

Any suggestions?

Henri.