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86 GW Vacuum Hose HELP!

Posted: Wed Dec 06, 2017 1:48 pm
by medicman85
Hey guys, first the pleasantries:
New member, first post, though I have been reading posts "from the shadows" for about 6 months now.

Ok, so I've reached a mental block trying to get my 86 GW vacuum hose situation under control. When I bought her, there were more bolts and plugs than there was hose as the previous owner only needed it to run well enough to get from hunting site to hunting site.

I've been following the diagram on the frame but this is the first year with the Ca smog/emissions (I believe?) and it's hard to make sense of it all even with the diagrams. :banghead: It has a Motorcraft 2150 carb, which I recently rebuilt, and will most likely need the exhausting replaced.

Alright, so, my issue right now is figuring out what this guy is:

The metal plate with 2 screws and the 2 metal lines coming out, one going to the carb and the other plugged.

This isn't represented in any of the available diagrams. Any ideas?

Re: 86 GW Vacuum Hose HELP!

Posted: Wed Dec 06, 2017 1:59 pm
by tgreese
It supplies hot air to the choke. The line that's plugged goes to a nipple on the air horn (that's the plate under the air cleaner, on top of the carburetor - part of the carburetor). Since that nipple comes from inside the filtered space, it supplies clean air to that plate in the manifold. Under the plate is a stove that heats the air by indirect contact with the exhaust gases. The tube coming up from the plate connects to the choke body with that brass nut. A small orificein the choke body draws the hot air by engine vacuum into the choke cover, where the hot air promotes the opening of the thermo-electric choke. You need both the hot air and the ignition connection (electricity) for the choke to work properly.

There is more about this in the section about fuel (carburetor, then choke circuit) in your TSM.

Re: 86 GW Vacuum Hose HELP!

Posted: Thu Dec 07, 2017 5:25 am
by medicman85
Wow, very concise tgreese, thank you.