One problem related to ignition has been reported for the 1998 Jaguar XJ8. The most recently reported issues are listed below.
The 1998 Xj8 while at highway / interstate speed 55 and up has gone into limp or stall mode at random (6 times in the past 18 months) exposing the occuptants to severe traffic hazards from fast moving vehicles. The vehicle coast to a standstill and must be put in park to restart. The Jaguar dealer has changed out parts but the problem continues. Many 1998 Jaguar owners have reported the same problem. The last incident was may 18, 2003.