About a week ago, my 1995 850 GL with 220K miles starting having what I would call a "high speed miss". I could feel some hesitation only when accelerating on the highway. It quickly progressed to having drivability issues at all speeds. It starts and idles fine, but when accelerating it hesitates continuosly now. It does not "miss" when cruising at constant speed or decelerating and I cannot reproduce this by revving the engine in neutral.

I would suspect the transmission since it only happens when in gear but this is a manual and it happens in all gears, so unless there is some way the clutch could be at fault (it shifts fine), I don't see that.

Before posting this I replaced the fuel filter and ignition coil with no improvement. Spark plugs were replaced about a month ago and ignition wires are about 2 years and 20K miles old. So the only item not new in the ignition stream is the distributor.

Anyone seen symptoms like this before? Any other likely causes you can think of?

Thanks, as always, in advance.