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Ford 300ci. What is this thing under the carburetor?

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ClydesdaleKevin:
This question is for my 1981 Ford F-100, which is our toad vehicle.  But might also apply to early Winnies with the Ford 300 straight six engine. 


What the heck is this thing under the carburetor?  It is a finned casting, sitting between the carb and the intake manifold, with a huge vacuum canister on the end that looks like a giant version of the vacuum advance on the distributor.  On mine, the vacuum hose isn't hooked up to anything.  What is it, what is it called, and what does it do?  Any ideas?


Thanks!


Kev

Rickf1985:
EGR valve. Recirculates exhaust gas through intake to control NOX emissions. If you don't have to pass an emissions test you don't really need it but keep a close ear for pinging.

ClydesdaleKevin:

--- Quote from: Rickf1985 on March 08, 2020, 09:34 AM ---EGR valve. Recirculates exhaust gas through intake to control NOX emissions. If you don't have to pass an emissions test you don't really need it but keep a close ear for pinging.

--- End quote ---

Thanks Rick!  I looked up the part, and it isn't too expensive...so I'll just replace it (and the gasket, which right now is literally a flattened piece of a Bud Light beer can...LOL).

Any idea where the vacuum line is supposed to attach to?  Mine is just hanging there, sitting on top of the valve cover.

Kev

Rickf1985:
I would have to look it up but it usually goes to a TVS (thermal Vacuum switch) on the water jacket, probably on the thermostat housing. Google the Ford light duty emissions system for the 300 or 4.9 and it should show the routing. The routing diagram should be on the radiator support or under the hood on a foil sticker. Might be on the air cleaner but that was mostly a GM thing.


The line goes from the EGR to the EGR solenoid and back to a port on the carb. So you may have an open vacuum line on the carb.

Gearhead88:

See if the emissions label is still under the hood some where , there will be a schematic of vacuum hose routing

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