sort of linked to my post below, cycling idle
 

i have an early 850 2.5 20v 1992, which uses the Bosch LH-3.2 system. i find the car has a tendancy to cycle its idle speed up and down by about 60 rpm, it also seems to misfire at about 2500 rpm to the extent you can hear a small break in the exhaust note every second or so. i also find the car quite thirsty, any ideas?

p.s. checked all the on board diagnostics no error codes found.

RE: sort of linked to my post below, cycling
 

have you checked for the air leaks?

Andy

RE: sort of linked to my post below, cycling
 

yes ive put a gauge on the inlet manifold and get about 19.5-20.5 hg, with a slow back and forth motion of the needle as the rpm goes up and down between 750-830.