What are these 2 small tubes in my Engine

[rutkak]

Gurus,

Does anyone know what the 2 small tubes (capped in Ford Blue) do and go to on both ends? They are outlined in red.

This is from a 70 302 w/California Emissions. The tubes are welded to Valve Cover clips and disappear into the firewall.

My guess is they run to what used to be the California Emissions junk on my gas tank...but what about in the engine? I would think they'd run to the carb or heck...maybe aircleaner but there's nothing on there for them to plug into. I also know they didn't go to the carbon canister since that was on the front passenger side underneath and I'm tracking that.

I'm resealing my intake manifold so I'll just yank out the metal and cap the tubing further up before it hits the firewall unless anyone thinks that's a REALLY bad course of action.

KR

 

[72HCODE]

i think that motor had an electronic distributor modular on it at one time.

more info

from the Cougar website:

"Distributor modulator system was standard equipment on some 1970 Ford Mercury Lincoln vehicles. We see it only on the 1970 Mercury Cougar and Ford Mustangs with the M code 351-4V Cleveland engine and FMX automatic transmission.

The purpose of the distributor modulator system was to help reduce carbon monoxide and hydrocarbons. Sometimes it is referred to as the Dist-o-vac system. The basic premise of the system was to use carburetor venturi vacuum to reduce engine emissions. This was performed by controlling distributor spark advance. A retarded spark provides hotter combustion chamber and exhaust manifold temperatures that cause more complete burning of the fuel.

The three main components are the Electronic Control Module, Speed Sensor, and Thermal Switch.

Electronic Control Module is the black box which houses the PC board and solenoid valve. Ford part D0AF-9E718-S, in the manual it is described as having a black box and a blue cover, we also see them with black covers on the black box.

*Side note – There is also a white colored box along with black, blue, and white covers. This combination of boxes and lids make for 6 differently identified units for a range of other applications.

Speed Sensor this actually is often confused with a cruise control part. It mounts inline on a two piece speedometer cable, it also has a two wire plug coming out of it. Ford part number D0AF-9E731-A.

Thermal Switch this measures temperatures and only engages the modulator system on, at temperatures above 58°F. Ford part number D0AF—12A164-B.

For a 1970 Mercury Cougar or Ford Mustang the black module box will 'cut in' at speeds of approximately 23 mph and 'cut out' when speeds fall below 18 mph, provided that ambient temperatures are about 58°F.

There is other related wiring and vacuum lines involved that we will try and include. There were also two similar systems on the 1972 Mercury Cougars. TRS Transmission Regulated Spark and ESC Electronic Spark Control are the names of the two systems. As time and information presents itself, we will include that system in the future."

 

[rutkak]

72HCode,

Wow, thank you very much for the information. I'll do some digging tomorrow and trace my old California emissions gas lines back to the black hole.

You rock. Seriously, that's incredible. I think it's a match...I'll see what else I can dig up.

KR


Actually, yeah that's it. I was rereading your post over and I thought I remembered seeing a box under the dash I didn't recognize.

I have doaf-9e718 under my dash. Interestingly, I don't have a 351W but it's definitely California Emissions stuff. That stuff is kind of pricey...sounds like I'll put it up on Ebay.

 

[72HCODE]

it appears to have been a 1970 only thing, the motor is from your 70s coupe?

you have the lines going into the dash that might mean the control box is still there. that would be pretty cool.

does the car have the 2 piece speedo cable? there should be the cable coming from the trans into a little box and another cable coming out going to the dash. if you have that little speed sensor box that would be pretty cool too. then just the vacuum controller and the temp sensor would be missing.

glad i could help

 

[1972 Green Mach]

Had th same setup on a 70 Lincoln Mark III. The control box is in the area near teh glove box. I had to follow the vacuum lines all the way back and forth to it. Surprisingly, it still seemed to work. A lot of the time the speed sensor was removed from the speedo cable sometime as a lot of people had no idea what it was and what it did. Seems like I recall the cars with it had a 2 piece speedo cable setup. When one side of the cable cores broke, the whole setup was trashed and a one piece cable put in. It has been a while since I worked on a Mustang setup I may be getting confused as to the speedo cable setup.

 

[72HCODE]

yup the 2 piece speedo cables disappeared from fords inventory so when they broke you ended up having to use the one piece and bypass the speed sensor. a lot of people confused it for the cruise control also.

once the speed sensor was bypassed the spark controller basically did nothing, so the emissions aspect of it was no longer used. then over time people removed pieces of it since it didn't work.

now you can get those parts as repops so a lot of people are restoring the emissions systems back on cars just to get concourse points and have the car as original as possible.

truth is as a Daily driver it makes the car happier because the engine burns cleaner, not good from performance but if you spend hours in the car and engine does less weird things you notice.