Fuel Distributer Question

[MattBelliveau]

89 300e, W124

So, short story long:

I removed my EHA and cracked it open to richen it a bit based on a post I read on here, to deal with some low power issues I had been having (stuttering/stumbling when giving more that a little fuel from a stop). After that, the car immediately started misfiring on Cyl #3 (even AFTER I adjusted the EHA back to the original settings). Swapped plug and wire, replaced EHA with a NEW unit, but the issue remained, so I assumed injector(s). Injectors have been replaced (by mechanic), but the problem persists; they said it was OVER fueling the cylinder (mechanic). Am I correct to assume the the fuel distributor is the next reasonable conclusion? I have a used one in hand, but the real question is this:

Has anyone ever had the experience of over-fueling on just one cylinder as a result of a FD heading south?