Why my Jag X type cant go beyond 3000rpm after conversion auto to Manual
#1
#2
Sounds like your car is in limp mode. This could be totally unrelated to your transmission swap. I would have to guess that you also have a warning light on the dash. Simplest place to start would be to have the codes read and then search on here for the cause. Coudl be somethning as simple as a vacuum leak or could be something a little more involved.