Distributer Modulator Valve

[Helicopter]

G'day all

    I found the DMV in the boot but can't for the life of me remember where it mounts.  There are two wires that look like they connect at the Aft, Right side of the engine (Pax side). 

     Also where do the vacuum lines go?

Ugh !!!  This Vac line installation is a pain.

TNX

Roy

 

[Carolina_Mountain_Mustangs]

What engine do you have? I can scan the Ford manual for the vacuum lines and send. I have 72 & 73 manuals no 71.

David

 

[Don C]

These may help you:

https://www.7173mustangs.com/thread-vacuum-hose-diagrams?pid=246021#pid246021

 

[Helicopter]

I knew there was something I forgot to add.

It is a '73  351 Cleveland 2V.

There are a boat load of Vac lines.  Whew !!

I think I have found where it Physically is attached to the engine. If I am right, it mounts to one of the valve cover bolts.

There is one bolt (not at correct location) which is especially made for it.

 

[rackerm]

I knew there was something I forgot to add.

It is a '73  351 Cleveland 2V.

There are a boat load of Vac lines.  Whew !!

Do you have A/C?

There are a bunch of vac lines for the A/C controls on the dash thru the firewall to the vac canister and heater hose control valve.

Then there are the engine vac lines and the power brake master cylinder. These may help...

 

[Helicopter]

My 351C is a 2V.

I am getting closer to getting them all sorted but still have no lines going to the Dist.Modulator valve (it has only 2 ports) and the EGR connection.

 

[Helicopter]

I think I have sorted-out the lion's share of the Vac hoses. The Tranny still waits until a high RPM before it shifts.

However, when I connect the distributor vac hose, the engine spits and sputters and runs very rough.

When I cap it and the hose off it runs real good.

Anybody have any ideas what is wrong?

 

[Hemikiller]

I think I have sorted-out the lion's share of the Vac hoses.  The Tranny still waits until a high RPM before it shifts.

However, when I connect the distributor vac hose, the engine spits and sputters and runs very rough.

When I cap it and the hose off it runs real good.  

Anybody have any ideas what is wrong?

Trans should be connected to direct manifold vacuum, usually the tree screwed into the intake, or the distribution block on the firewall. The 73 had a dual diaphragm vacuum modulator on the transmission, which was hooked into the EGR system on it's secondary port. To my knowledge, the dual diaphragm modulators are no longer made. 

Found this PDF of the 73 vacuum diagrams here on this site. Looks like you need to use 3-14A.

https://www.7173mustangs.com/attachment.php?aid=12588

IMO, you need to start from square one. Verify the trans vacuum line is good and hooked up correctly. Cap all the vacuum lines and reset the engine timing and idle speed to the factory specs. If the engine idle changes when you hook up the vacuum to the distributor, you have it on the wrong vac port on the carb. Fords of this era use ported vacuum for the dizzy, which only works when the throttle is opened. Under normal conditions, there should never be vaccum present at the distributor at idle. 

FWIW, it sounds to me like you're flying blind and don't have a factory shop manual. Do yourself a huge favor and make the investment. It's $70, but goes a long way toward answering many of the questions you've asked here. 

http://www.mustangsunlimited.com/Mustang/Literature/Manuals/Shop-Manuals/Shop-Manual-5-Volume-1973-Mustang-Cougar-Ford.axd

Oh, and if you think a 73 Mustang has a lot of vacuum lines, you should look at some of the 70's and 80's Chrysler vehicles - whoa....