Hi, I own a Sierra 4x4 (2.9i) ever since I've owned it (approx 2.5 years) about every 4 - 5 weeks it backfires & completely cuts out -& after about 10 mins or so it will re-start!. Usually I get a warning of a backfire or 2 but the other week it caught me on the fast lane of a motorway thank God there was nothing behind me - I've taken it to 2 garages who cant find the problem, has anyone have any idea what might be causing this. Is the backfiring a sign of a spark with no fuel which that could mean fuel pump on its way out or is it something to do with the engine management system which I suspect the previous owner has fiddled around with.
Any advice/help would be much appreciated as I don't know where to start!
Dave