1978 MERCURY GRAND MARQUIS 6.6L 400cid V8
 

1978 MERCURY GRAND MARQUIS 6.6L 400cid V8
hi can anyone help me i brought this car a week ago it is a lovely car has been driving perfectly yesterday i was driving down the motorway it lost power and chugged a long at slow speed so i pulled over turned the engine off restarted it car drove perfect for a mile then it started coughing this is all it will do every mile. have new fuel filters fuel pump seems fine can anyone help please.
i live in the uk the car has only done 40,000 mile