We have just got my 1983 XJS running. We took it out for a ride and it didn't shift until 4000 rpm's. It seemed fairly high but I have no experience with theses cars. So my question is, what is the normal rpm’s for it to shift at? Thanks.

 

Not normal...unless you are using a lot of throttle.

You have a faulty vacuum modulator or the vacuum hose to the module is broken/disconnected.

Cheers
DD

 

depending on how your driving determines the shift point. just tooling around town i shift around 2000

 

Where is the hose located? The engine has acts like it has a vacume leak so there is a good chance that may be the problem.
Thanks.

 

Near the rear of the right side cylinder head or cam cover.....my memory won't generate anything more specific than that, sorry.

Might be easier to trace it upwards from the trans.

The vacuum modulator is on the right side of the trans...a small cannister type of device. You'll see it

Cheers
DD