Outer Limits 4x4 Board

Could someone please tell me where the vaccum line off the air con idle diaphram on the injection pump goes.
I noticed it was not hooked up and for the life of me can not see where it goes.

The hose goes from the idle up unit to the solenoid on the firewall, then from the solenoid to the outlet on the rear of the vacuum pump (on the back of the alternator) . There is a screw on the rear of the idle up unit to adjust the speed

Can any one tell me were this "Fast Idle" adjustment thing is on an old TB42, as there is no vac pump of the alternator.
I'm having the problem in that my TB42 idles nicely at approx 600rpm but when the A/C is turned on she drops close to 400rpm and stuters.

Thanks tuffzook I had a look at that solenoid but couldnt see any where you could attach the line, is it near were the line from the alternator goes in?