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VALVE ASSY, DISTRIBUTOR VACUUM CONTROL, 3 PORT


Full Description
VALVE ASSY, DISTRIBUTOR VACUUM CONTROL, 3 PORT
(5)
Item # 12A091-8A
MPN # 12A091-8A

$24.95
In Stock!




In Store Availability
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NC
MI
CA
Description

VALVE ASSY, Distributor Vacuum Control, 3 port, mounts to thermostat housing, exactly like the original without the original markings (has small *IH* logo), Made by the original supplier on the original tools with correct finishes, Missing only the correct markings, See 980-4 for installation tool, ** Note: We have found that most of these valves are activating at around 125 degrees instead of the intended 225 degrees, What does this mean? 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 : 12A091-8A
Manufacturer Reference #'s: C8AZ-12A091-A, MY126, C8AZ-12A091-A, D5VY-12A091-A, D7AZ-12A091-A

Vehicle Information

Year-Range (bold)      Model (bold)      Fits/Applications

1968-1973 MUSTANG 289, 302, 351C, 351W, 390, 428

1969-1973 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)

1968-1971 FAIRLANE FAIRLANE, TORINO, 70 1/2 FALCON

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 8 CYL., ID# D7AE-B1A

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.

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Reviews

4 Star Avg.
5 Reviews

80% of reviewers recommend this product.

Write a Review
Verified Buyer VALVE ASSY, DISTRIBUTOR VACUUM CONTROL, 3 PORT

good quality item

Submitted on June 15, 2019 by

YES I would recommend this product.

Quality

5 Stars

Value

5 Stars

Verified Buyer VALVE ASSY, DISTRIBUTOR VACUUM CONTROL, 3 PORT

Fit and finish very close to original part. Having to swap hoses per the enclosed instructions is minor.

Submitted on April 26, 2020 by

YES I would recommend this product.

Quality

5 Stars

Value

5 Stars

Verified Buyer VALVE ASSY, DISTRIBUTOR VACUUM CONTROL, 3 PORT

The vacuum control valve looks nice, but due to issues I’ve had with various reproduction parts over the years, I decided to test it prior to installation. Using a small pot of warmed water, I found that the valve switched from port 1 to port 2 at 135 degrees Fahrenheit (perhaps even lower, I didn’t bother testing with cooler water). It shouldn’t switch ports until about 215-225 F. Upon reporting this to NPD, they promptly refunded my purchase. This item is only good for a trailer queen that you want to appear original. If you want a valve that works how the factory one works, buy the other one.

Submitted on March 16, 2023 by

Quality

2 Stars

Value

2 Stars

VALVE ASSY, DISTRIBUTOR VACUUM CONTROL, 3 PORT

This product is built and designed correctly. Do not be mislead even by NPD as to the 125 / 225 temp issue. I have shop manuals and am a factory trained dealership technician retired. I will tell you that there are two different ported vacuum switches for dual diaphragm distributor timing control. This product at 125F shift point is correct for the delaying of vacuum advance on a cold engine. There is a separate valve that is rated at 225F to shift full vacuum to the advance diaphragm to aid in cooling the engine when starting to overheat, namely, in extended idle, in drive with AC on in hot weather. There is NOTHING wrong with this part and it is grand that it is still available for CORRECT dual diaphragm IMCO emissions control in the 1970 model year...and maybe more years...do not be afraid of this product.

Submitted on January 01, 2024 by

YES I would recommend this product.

NPD - National Parts Depot

For the purist the original opened at 225. These open at 125 which is what Ford and most other manufacturers went to in 1974 to retard ignition earlier and help limit emissions.

Quality

5 Stars

Value

5 Stars

VALVE ASSY, DISTRIBUTOR VACUUM CONTROL, 3 PORT

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

YES I would recommend this product.

Quality

5 Stars

Value

5 Stars