Sometimes when I start the car and try to drive HER the engine will rev but not go, if I let off the gas for a second and try again its fine. it has happened to to me twice in the last 2 days, only when the engine is cold and only right after I turn the car on. On one of the days I let her warm up for about 10 minutes before driving and she drove beautifully. If anyone has a fairly good what this could be let me know.
This is a 1990 xjs v12 convertible

 

Have you checked the fluid level ?

Cheers
DD

 

As Doug said, and also how long since the transmission filter was changed, it may be clogging up and preventing flow of the "cold" fluid, and once warmer all is fine.

This scenario is RARE, as compared to the fluid level being tooooooo low.

Make sure SHE is at normal operating temp, on level ground, and check the fluid level with the engine running in "P".