Help! Eng surging & won't rev over 2000

[Laddie]

Hi, new, first post
Help, have 1993, e30, Cabrio, 325iC

A. Rough idle but smoothes out when airCond is turned on

B. Won't rev above 2000 rpm

Any help/ experience??
Thank You
Laddie

[Stanley Rockafella]

Icv