I wish I could help with the rough running. Clogged or bad injector? 
(are 84's injected?)  Of all the things I've fixed on our '90 (almost 
everything) the engine's always run like a top- EXCEPT when the local 
FLAPS ran out of Bosch plugs and I put in a set of Autolite platinums.  
Within 4mos the van would almost die whenever we stepped on the gas. I 
pulled the plugs, the electrodes looked fine but the little tabs on 
the other end of the spark were almost burned off. I put in a set of 
Bosch platinums and it's run well ever since.(This is only the 4th set 
of plugs in about 150K miles).

Dan Fuller
'90 Carat
'63 Ragtop bug
'95 BMW 318ic