318 spluttering

[paul007]

i have a 318i convertible
i was on the motorway yesterday and out of the blue it started spluttering -when i accelerated it retarded even more.
when i stopped it was idling fine -however when i drove off again it jerked and spluttered to the point i thought it would stop.

i called the rac but by the timed they arrived the car was ok. however he unscrewed and screwed back the airflow sensor cap saying this can be a problem sometimes.

today it started spluttering again as i was driving, so i stopped and unscrewed /screwed back the airflow sensor cap. the car was ok for a bit then it started again.
any help greatly appreciated.

[Speedtouch]

Could be all manner of things, ranging from a dodgy batch of fuel, blocked fuel filter, perished fuel hoses, failing spark plugs/distributor cap/rotor arm/ignition coil, loose engine-to-body earth strap, failing DME relay, etc.

You need to methodically go through and check these.

[Billwill]

What is an airflow sensor cap?

Is this an M40 or M10 318i?

[paul007]

its a m40 and the cap is the tube that joins the air flow sensor i guess you have to unscrew it to take it off.
i think it defo has something to do with that as now when it starts to misfire when i unsrew and srew the cap back on its ok for a while.