Thermal Valve Vacuum Line

XJ
1

I have a 76 XJC V12 with an HE engine swap. Trying to figure out where the vacuum line goes from the thermal valve. The vacuum line with the vacuum delay valve is disconnected and not sure where it goes.

Thanks,
Darrin

2

This is in conjunction with the 45 sec timer and a three way solenoid valve that kills the vacuum advance when the engine is cold to help the cats light up.
You can delete it if you want with no ill effects.

3

Thanks. Just a follow up. Can one delete the whole thermal valve or just the vacuum line I mentioned?

4

My car did not have the thermal valve.
Different markets have different emissions configurations.

I deleted the vacuum advance kill on startup, now the 45 sec time operates just the Extra Air valve.
The vacuum advance is connected to a ported vacuum via the vacuum delay valve.
Have a look at Kirby’s book, it explains the system in great detail.

5

There is some uncertainty as to the importance of the various ‘extras’ fitted to the HE, Darrin. Some related to emission, some to engine well-being. Jaguar of course wanted the engine to perform flawlessly cold or hot under any driving conditions - while keeping it within emission limits in relevant markets; the set-ups differ.

You can try - and see what happens…

Frank
xj6 85 Sov Europe (UK/NZ)