Hi need some advice on the heater control valve. When I bought the car the heater was not working found out it had a core leak have taken out the defected core [what a job] and waiting for replacement,however the previous owner for whatever reason had removed the heater control valve. I have one on order but I am unsure where the vacuum from the control valve goes to as I cannot see where he may have cut it or more than likely pulled it out. Is this set up similar to Z32? I cannot find any link in the workshop manual I'm assuming the valve works by vacuum which opens up the valve allowing heated coolant through into the heater core can anyone throw some light on this Thanks in advance Coopz.
The water cock works via vacuum. It gets it's vacuum from the vacuum tank, located RH(driver) front side behind the headlight as it were. If you have a downloaded FSM http://www.xenonzcar.com/z31/reference.html HA (heater/aircon) page 3 shows the layout. And page 5 shows little diagrams
Thanks for info. Just one more thing does the vacuum pump turn on when you turn on ignition on [should you hear it running] or does it come on when you switch the heater on thanks
Turbo vacuum pump only turns on when vacuum pressure is low (and if vacuum is required when engine is in boost) or if there's a vacuum leak.