VALVE ASSY, Distributor Vacuum Control, 3 port, replacement, mounts to thermostat housing, See also 12A091-8A for more correct valve, 12A091-1A, 12A091-1 and 980-4 for installation tool, ** At idle, under normal engine operating temperatures, the distributor advance (center port) runs off of ported vacuum from the carburetor (upper port) which is 0 psi at idle, During extended idling, on a hot day, maybe with the A/C on, engine temps can start to rise, When the coolant temperature exceeds about 225 degrees, this valve closes the ported carburetor vacuum port and opens the non-ported vacuum (lower port) from the intake manifold, Non-ported vacuum at idle is normally high (12-15 psi), and this causes the distributor vacuum advance to advance the timing which results in an increase of the idle speed (about 100 rpm), spinning the radiator fan faster and drawing more air through the radiator helping to cool the engine, When engine temps reduce to a certain point, the valve closes and resumes using ported vacuum, None of this effects the engine while driving as the distributor is already running an advance to the timing as speed increases, **
NPD Part Number : 12A091-1B Manufacturer Reference #'s: PVS14,
1968-1973 MUSTANG 289, 302, 351C, 351W, 390, 428
1968-1973 MUSTANG 200, 250
1979-1979 MUSTANG 2.8L, A/T, CALIFORNIA, ID# D7AE-B1A
1979-1979 MUSTANG 5.0, M/T, EXCL CALIFORNIA, ID# D7AE-B1A
1980-1980 MUSTANG 3.3L, A/T, CALIFORNIA, ID# D7AE-A1A, A2A, B1A, B2A
1967-1973 COUGAR 289, 302, 351C, 351W, 390, 427, 428
1968-1970 FALCON (BEFORE 1/1/70)
1973-1974 F100 360, 390
1974-1974 F100 302, A/T
1974-1974 F100 302, M/T AND A/C
1974-1974 F100 460
1976-1976 F100 302, CALIFORNIA
1971-1973 F100 4X2
1971-1973 F100 4X2 360, 390, SUPER COOLING
1975-1975 F100-F350 360, 390, A/C
1971-1973 F250, F350 SUPER COOLING
1969-1972 BRONCO 170
1973-1977 BRONCO 302, ID# D7AE-B1A
1978-1979 BRONCO 302, ID# D7AE-B1A
1970-1970 FALCON (FROM 1/1/70)
1968-1971 TORINO
1968-1970 FAIRLANE
WARNING: This product can expose you to chemicals including lead and DEHP, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
NPD sells three ported vacuum switches. The issue of what temperature the switch changes is questioned and therefore confusion. I know from dealership technician experience that the factory Ford switches are stamped with the op temp on the wax button that screws into the engine. The switch that operates at 225 is for extended idle overheat control in hot weather, with AC on. The switch that operates at 125 is for cold engine warm up. Make sure you use the correct PVS for the control you are after, either overheat or cold engine warm up.
Submitted on January 01, 2024 by Chuck G.
YES I would recommend this product.
Quality
Value