It's a smashed distributor vacuum control valve. It's purpose was to speed up the idle to cool the engine if the coolant got to 220°. Many people bypassed or removed them under the mistaken belief they were "pollution equipment mandated by the government to rob the engine of power". I can refer you to Ford vacuum diagrams to re-install this handy system if you like.
This little device may not appear to be all that important, but it has a big job to do when your engine gets too hot. The threaded end looks a bit like an engine temperature sensor, and that's because it is. It's normally mounted on the intake manifold or engine block where it can sense coolant temperature.
The three ports at the other end are for vacuum connections. One goes to manifold vacuum, another to carburetor vacuum, and the third goes to the vacuum advance on the distributor. At normal engine temperatures, the distributor gets ported vacuum, which is 0 psi at idle. During extended idling on a hot day in bumper to bumper traffic, the engine temperature can start to rise pretty fast, especially with air conditioning on. That's when this little device goes to work. When engine temperatures reach about 225 degrees, this switch changes the distributor vacuum advance source from ported to manifold vacuum, which is high at idle. This advances the timing and engine rpm increases.
The result is increased radiator fan speed and coolant flow through the engine and radiator, which tends to bring the temperature down. Once the sensor determines the coolant temperatures have dropped to a safe level, it reverts back to ported vacuum and the engine timing returns to normal, returning the idle rpm to its normal setting.
Chances are most people have never even noticed when this device is protecting their engine, they just notice that the temperature gauge drops a bit, or the HOT light on the instrument panel extinguishes.
well, actually i may not be totally correct on this one as i found the info below that backs up 2+2GT, however i know have seen other info that states what i said as well. anyway, here is the info i found
I think the temperature sensor is the device in the manifold just above and left of the red circle. This car has the factory oil/alt/temp gauge cluster in the center console. It's been so long since I've actually driven it that I can't say if any of them work. I'll check when I get it re-assembled.On my 1970 351 2V Cleveland, thats the temperature sensor. Does your temp gauge work? If it a smashed vacuum thing like stated above, the motor is gunna run like crap or your tranny (if its auto) is gunna have a really hard time shifting.
On my 1970 351 2V Cleveland, thats the temperature sensor. Does your temp gauge work? If it a smashed vacuum thing like stated above, the motor is gunna run like crap or your tranny (if its auto) is gunna have a really hard time shifting.
I'd like to setup the vacuum system as originally intended, but that may not be possible. The vacuum switches seem easy enough to find, but I haven't been able to locate the two normally open solenoid valves, the check valve, and the spark delay valve. I also assume that somewhere I should be able to locate (item 9) the "ambient temperature switch", but the shop manual doesn't seem to be much help in telling me where to look for it. I suppose that could be missing too since the solenoid valve it's supposed to connect to isn't there.