Dan says:
"The regina coil is a common source of problems...", but I must politely disagree, based on 11 years of owning and maintaining my '93 Regina 940, plus about 7 or 8 years on another '92 940. During that time I've been scanning here almost daily to learn what I could about the Regina's common complaints, of which the coil was sometimes offered as a suggestion but seldom proven to be at fault. However, if you want to go down that road I can post a couple of photos showing what's involved.

But you've offered a lot of possibilities, starting with the fuel pump 2 years ago, after which the car "never ran right".
What was the new pump's source/brand?
Who installed it (Family? Dealer? Local independent shop? etc.)
What is the current fuel pressure at idle?
Are you still getting OBD codes? If so, what are they (socket 2 and 6)?
What brand and and type is the "new"O2 sensor? The Regina type is unique, but long-lived. Bosch type won't work (for long).

Has the timing belt been checked for possible slippage? (yes, a cog-belt can jump out of sync)
And do you know how many miles it has on it?

Guess that's enough to get the ball rolling.
I'll be watching for your reply.



--
Bruce Young, '93 940-NA (current), 240s (one V8), 140s, 122s, since '63.