I have a 1999 Jaguar XJ8 Vanden Plas. It has 167,000
miles on it and was running great. Still does except when it spontaneously quits! It will run for give or take 2 hours and then it quits. You can put it in neutral and it starts up and it may run for 15 minutes or 2 more hours before she quits again. It takes several of these shut offs before you get a check engine light. The code is P0121.
She is a great car and I would love to be able to trust it to run until I shut her off. They do not make new throttle position sensors anymore. Any ideas?