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Discussion Starter · #1 ·
I need help identifying a component which is connected to the coolant temperature vacuum switch. For starters, I have a '79 Fairmont with a 200 ci six and a C-4 transmission. The temperature vacuum switch (located on the thermostat housing) has two plastic tubes connected to it. One of those tubes is green and goes straight to the EGR valve actuator. The other tube is white and connects to the mystery component. On the other side of the mystery component is an orange plastic hose that connects to the carburetor. The mystery component is made of metal (it looks quite a bit like a vacuum motor) and has a sticker on it with the number D6AE-9F424-AIA. Can anybody tell me what this thing is?
 

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A picture would be helpful. I have 2 different 6 cylinder engines.
But am having a hard time figuring out which part you are talking about.
Could it be the "WOT" valve?
aimg9.imageshack.us_img9_4513_wotvalve.jpg
 

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Discussion Starter · #4 ·
Red 78'-
I think you nailed it despite an error in my description. A closer inspection shows that the green plastic hose goes from the temperature vacuum switch into the "mystery component" and then another green plastic hose connects to the same side of the "mystery component" and then connects to the EGR valve actuator at the other end. The orange hose DOES connect the to other side of the "mystery component" (opposite the green plastic hose) on one end and to the carburetor on the other end (under the air cleaner flange on the driver's side). The white plastic hose coming from the temperature vacuum switch connects to the carburetor on the passenger side of the carburetor body. I'll do some more investigating and try to find my digital camera. But for the fact that I can't find it, I'd have posted a picture. By the way, what the heck does the WOT valve do?
 

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Discussion Starter · #5 ·
Now for the next dumb question: how do I test the WOT valve to make sure it's working correctly?
 

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I'm sorry, the correct name is vacuum load control valve.
I have been calling it "WOT" for over 30 years, it's hard to change old habits.
First make sure it its hooked up correctly. Go to Autozone.com, enter your vehicle, click on vehicle repair guides, emission controles, vacuum diagrams, and "find your motor, or one that looks like it has the same stuff on it.
I have the instructions for testing it, but it must be hooked up correctly to do any good.


 

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Glad I found this thread, always wondered what the heck that thing was.
 

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Ok, this is what the Ford manual says it does,

EGR SYSTEM WOT (WIDE OPEN THROTTLE) LOAD CONTROL VALVE

Some EGR systems feature a load control valve that closes the EGR valve when the engine requires maximum power at or near wide open throttle.

The WOT valve is installed in the vacuum line between the ported vacuum connection on the carburetor and the EGR valve. A vacuum line from the carburetor venturi vacuum tap is connected to the top part on the WOT valve and provides control for the valve. When venturi vacuum is at a predetermined level near wide open throttle, it is strong enough to overcome the calibration spring pressure and unseat the diaphragm valve, diverting EGR source vacuum to the atmosphere and causing the EGR valve to close. Normal EGR flow is resumed when there is a reduction in engine load from the wide open throttle condition.
 

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I always wondered what it was. i snapped one on my 79 inline6 and i just pulled it out of the 80 mont i had lying around...
 

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A picture would be helpful. I have 2 different 6 cylinder engines.
But am having a hard time figuring out which part you are talking about.
Could it be the "WOT" valve?
aimg9.imageshack.us_img9_4513_wotvalve.jpg
I still can't get over how clean your engine is! i've never seen one that clean before...
 
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