Hi, wonder if anyone can help. I own a 1992 g60 and recently the engine revs have become erratic on idle. They drop until it nearly stalls then kicks back in. Under power it starts to chug( the sort of feeling as you are running out of petrol ). Above about 2500 revs the problem seems to dissappear. A mechanic friend has changed the plug leads, rotary arm and dis cap but the problem remains, he has also hooked it up to a electronic diagnostic box but there were no faults found. It has been serviced. Any ideas anyone