1994 Jaguar XJS Q&A

1994 Jaguar XJS Question: back fire

backfire at low rpm ,also will not rev from an idle,sputters and backfires. changed fuel pump,filter,mass air. -
Answer 1
I would have the catalytic converter inspected for a possible restriction. Also check for any vacuum leaks or an air leak somewhere. -
Answer 2
Crank shaft position senor failure on that model can do this as well but proper tests for vacuum leaks and looking at key sensor values on an oscilloscope may show what the true problem is. -