Zingari

Whilst having the evaporator swapped to sort the AC my Indy has discovered a vacuum valve behind the dash directly behind the HVAC module fastened to the bulkhead. It has a connector for a pipe but it is not connected up. Does anyone know what it's for and if and where it schould be connected up to?

Should have taken a picture but too shocked seing the car with no fuel tank in it given the amount that needs to come out to change the evaporator!

jenskleis

Is sounds to me as if your wrench has stumbled across the vacuum valve for the air re-circulation flap.

Zingari

Hmm - so where does the pipe go to and from then as there was no piping there?

ToreB

It is the resirculation flap. A thin pipe is routed along with the electrical harness from the engine to the electric vacuum valve in the trunk. A pipe then goes from the valve to the actuator on the flap.
The pipes are about 4mm in diameter and white or black in colour, can be mistaken for an electric wire. Are you sure it's not there?
See my web page for details:
www.ccu.tore.bergvill.com
Cheers,
Tore

Zingari

Tore thanks but from recollection when I saw it, the valve looks more like the mushroom style with a tube/lip coming out of the bottom (mounted side on) for a rubber tube to push over it.

Also noticed on your site the rear vacuum valve next to it the solenoid has a pipe coming out of the top (I have highlighted it in yellow) This does not seem to be connected up in the UK as my fellow 911UK chums all have the rubber curved pipe but nothing attached to it.