Thermo pneumatic valve.

[rob hod]

    I've been on the case of some enrichment issues and found that the vac.
line to the diaphragm pressure switch had been messed with to bypass the
thermo-pneumatic valve mounted in the head. This would mean I'm getting
acceleration enrichment at all times.

    What i'd like to know is if the TP valve is directional and at what
temperature the valve opens and closes. With the engine run for a couple of
minutes coolant temp maybe 75F, but by no means at operating temp the valve
i'm looking at seems to be closed. Ambient temp today is about 70F.  Any
BTDT?

    TIA

rob