i have a 1984 930 with a big problem. the problem is that over 3000 rpms the car goes pig rich, which ends up fouling out the plugs. fuel pressure at cold idle is 55 between WUR and fuel dist this is on a 65 degree day . and 50 when warm (just about to enter the normal range, never gets hotter than that). The car goes through spark plugs like crazy, but when you put new plugs in, the car runs fine above 3000. new WUR and rebuilt fuel distributor. also when first started the car runs like junk. spitting, popping, and when you press the gas pedal, it just get worse as if it wants to die but after ~1 minute it returns to normal. today i noticed that the vacuum line between the WUR and the air box was unplugged, could this be the problem, or is it something more serious?

 

Try doing a test run with the O2 sensor unplugged. I had a similar issue and without the O2 sensor, I was fine.

 

Oh wait.. you don't have an O2 sensor in your car do you?? never mind..

 

nope no o2 sensor, my '87 does though.

 

"today i noticed that the vacuum line between the WUR and the air box was unplugged, could this be the problem, or is it something more serious?"

If you are referring to the line underneath the WUR and goes to the throttle body, then yes, that could very well be causing your problems.
If were some sort of vacuum leak, your engine would be running lean. The hose you refer to feeds a diaphragm which controls the fuel pressure under vacuum/boost conditions.
Go for it and let's us know how it goes.

 

no the line from the airbox to the WUR was disconnected

 

I think the line you are referring to is a vent line for the WUR and I doubt it being disconnected could cause the problems that you describe. However, I do belive that the issue could be related to your "rebuilt" WUR and fuel dizzy. Tell us about what was done. How were your AFRs (air fuel ratio) set? What are your WUR pressure readings, again?