sorry, incorrect term used. the car hadnt been run for a long time, and had to have a new metering head (ive known the car for ages which is handy)
the phirm (i think thats how its spelt, they deal with alot of bmw i think (some one correct me if im wrong)) fitted the unit and adjusted the fueling to its correct level. he said that after a few weeks it wil start to over fuel and pop and bang in and out of gears changes and will need the fuel pressure turning down slightly.
the car was fine for a few weeks (went out in it the day it was done) before starting to pop and bang......

will probably get it then have the fueling checked..