Mystery electrical plug and vacuum line on top of valve cover?

[theskyisoutthere]

I never claim to know it all or even most but this is stumping me.  What is this thing sitting over the valve cover with the wires and the vac line,  its unplugged from the vac on one end and the other end is an open hose to no where.    It has two wires going to it.


i??

[DaveVA78Chieftain]

I  suspect it is the vacuum solenoid valve for the Vacuum Throttle Position System used on the Holley Model 2245 carburetor used on California based 360's.  Page 14-17 of the 76-77 Dodge MH Service manual.

Dave

[Rickf1985]

The 2245 and the 7870 are different versions of the same carb. It was probably replaced as a rebuild in the past.

This will give you an idea of how popular that carb was. Look at the applications and then at the bottom of the page look at all of the carb numbers the kit services.
http://quadrajetparts.com/holley-carburetor-parts-holley-2209-2210-2245-rebuild-kits-holley-2210-2245-carburetor-rebuild-kit-4082d-1967-mopar-1963-p-1538.html

[DaveVA78Chieftain]

2245 is the Model series.  There are several versions of that Model

76-79 Federal and Canada used version R-7088A of the Model 2245

76-77 California used version R-7090A of the Model 2245
78-79 California used version R-8028A of the Model 2245

Appears someone has changed you setup.

Dave

[Rickf1985]

That is why I am not a teacher, You say it in a way that makes sense.  D:oH!

[PwrWgnWalt]

Hi Sky;

The gizmo you picture is, methinks, an example of the early attempt by Ma Mopar at emission control. 
A very similar setup is found on early 70's autos and trucks (& into the 80's in some manner), called the "NOx Vacuum Valve Solenoid".  The wires and plug appear the same;  see my post & pic (5th Topic) at:  http://www.sweptline.org/forums/viewtopic.php?f=21&t=34977   


Be sure to look at the second picture therein, including the plug tucked behind wires at upper left.
The first picture there shows the Temperature Switch for the automatic transmission models.
A Red wire from the "Run" side of the Ballast Resistor goes to picture #1, and on to the NOx valve in picture #2.
My Yellow wire in picture #2 came from a plug-in at picture #1.
The third piece of this early NOx was a Speed Switch, mounted on Transmission where the speedo cable attaches.
This system in 1971 used a 185* thermostat, high overlap cam, and three unique pieces, as above.

"The NOx system is designed to prevent vacuum spark advance when
(1) the (underhood) temperature is above 70*F,
(2) speed is below 30 mph and
(3) the truck is accelerating.
Whenever all three of these conditions exist, the solenoid vacuum valve will be energized, venting the distributor vacuum advance chamber and shutting off the vacuum from the carburetor."

The nipple on the side of the Vacuum Valve with the plug prongs goes to carburetor vacuum (T'd into the Distributor vacuum advance line).
The nipple at the rear (underside) of the Vacuum Valve is supposed to have a foam filter over it, as it is supposed to bleed off vacuum being applied to the distributor.  Does that rubber hose go anywhere, on yours?  If it goes to the distributor, yours may have the OSAC system and/or an EGR Valve... in 1973 one, or both, of these replaced the earliest ('70-'72) system described above, at least in passenger cars. 

Here's a current eBay auction for a similar item http://www.ebay.com/itm/NOS-71-85-VACUUM-NOX-VALVE-3656381-3438474-CUDA-CHALLENGER-CHARGER-GTX-DODGE-/231256500850

As you might expect, most of these early Emission Control gizmos have been disconnected, discarded, etc.

Hope this helps! W%
- Walt