I am installing air conditioning on my MK2, and I have wondered about the need to install some type of idle "kick-up" solenoid to assist with low idle speed when sitting at a traffic light and the compressor kicks in. Anyone here done this? Any tips would be appreciated, video or picks would be great, making a perfect mounting bracket for me would be over the top! Hah, just kidding but it would be nice. :-)

Lin

 

On the automatics you have a switch between the carbs which operates a valve on the rear brakes when you are sitting in traffic.

If you find that the AC requires too much power for the engine at idle then you could wire a relay into this circuit so that when the switch is active (at idle) the AC clutch is disengaged.

I can't see why this wouldn't work but you wouldn't have AC when sitting in traffic jams which would be undesirable.

I would have thought a big engine like the XK would be able to run the AC at idle.

On production cars they have a WOT relay (wide open throttle relay) which disengages the AC when you put you foot to the floor to give a bit more power for overtaking. You could probably do something like this with a switch on the throttle linkage.

Good Luck!

 

Jaguar used a kick-up system on (at least ) the HE V12 engines and *some* of the 4.2 XK engines used in the Series III XJ6... and even offered it as a retro-fit package. The Harrison A6 compressors used on those models creates quite a load.

But....

The compressor you install might not be so parasitic and might not load the engine as heavily.

I'd wait and see, then decide

Cheers
DD

 

My 3.8 Mk 2 has its original 1966 AC unit including the York compressor. It has no problem at idle and it does not have an increased idle speed. The ammeter reading is another thing, however, because the car is almost entirely original, which means that it runs on the original positive ground generator. But I don' spend much time at stop lights and never in idling traffic.