400 Vacuum Questions
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400 Vacuum Questions
I have a 400 in my 1978 Ranchero GT. On the passenger side of the intake manifold is a plate that contains a small S-shaped tube that provides heat to the choke. Next to it is a piece of metal tubing with a 90 degree bend that is connected to a piece of vacuum tubing. The other end isn't connected to anything. It pulls something like 22mmHG of vacuum at idle. Any ideas where it goes?
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400 Vacuum Questions
I have a '77 Ranchero with a 400M. I just transplanted the engine/trans into a '71 F350. I still have all the vacuum and wiring diagrams and my notes at home. If no one answers you before tomorrow I will let you know.
Bruce
Bruce
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400 Vacuum Questions
If the air cleaner is original, did you look on the bottom side of it to see if there is a vacuum line hook up? I had 400 Ranchero years ago but,don't remember. The vacuum line may go to the bottom of the air cleaner. If you have an after market air cleaner all you can do is plug it.
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400 Vacuum Questions
Don't plug it or the choke won't work properly. If you don't have a place on the air cleaner for it, then check the back of the carb. Most Ford 2barrels have a port on the top rear (it sticks through the flat part behind the choke butterfly) hooking it to that would have the same effect as the bottom of the air cleaner.
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400 Vacuum Questions
John:
Marty is right. On my ’77 it hooked to a vacuum port on the underside of the flat part of the 2bbl carb. This port just passes through to the top side of the carb and provides clean air to be sucked in through the choke’s vacuum port.
Good Luck.
Bruce.
Marty is right. On my ’77 it hooked to a vacuum port on the underside of the flat part of the 2bbl carb. This port just passes through to the top side of the carb and provides clean air to be sucked in through the choke’s vacuum port.
Good Luck.
Bruce.
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