Paul Foster

I found that a vacuum line from what appears to be the Vacuum Check Valve under the intake manifold at about the #3 cylinder is not connected to anything. According to Lindsay Racing:

"This vacuum valve closes when the car goes under boost and traps the vacuum after the valve to maintain the vacuum necessary to control the heater and A/C systems.". So I presume it goes through the firewall. someplace but I can't find where.

https://www.lindseyracing.com/LR/Por...37-361-02.html

I also noticed that the vacuum line from fuel cannister shutoff valve is supposed to be connected to a Thermo Vacuum Valve:

https://www.lindseyracing.com/LR/Por...131-851-A.html

But I cannot find it.

Any help resolving these two issues would be appreciated.

mikeyoman

Hi Paul,

Attached some pics & docs to help you.
The vac line from the Blue Check valve should go to a small Black reservoir canister near the battery tray, about the size of a Coke can, used for Heating control actuation. From there the vac line goes through the firewall to the heater/AC unit actuators.
The small vac switch is located under the intake manifold near the boost control valve (correct name ?). Intake may have to come off to get to it !


Boost control valve near oil filler


vac switch next to boost control valve

Paul Foster

Thanks! I finally managed to locate the temp valve and find a home for the connection. Ditto with the one from the check valve.

The 944 is so easy to work on compared to the 951. Porsche really turned it into the spawn of Satan adding the turbo on after the fact.