Vacuum source for heater control valve

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   Working on my dad's 2nd 77 Gremlin, this one a bone stock 232 with AC.  I've removed the air injection system and the two thermostatic vacuum switches from the side of the block.  During this modification, I came across the heater control valve vacuum hose...and what I'm guessing is its source connection - a J-Shaped hard line.  It 'appears' to fit in the choke heater tube that protrudes from the bottom of the exhaust manifold.There's no retention on the tube when installed, and of course it was zip-tied to a conglomeration of tee'd and plugged vacuum hoses that ended up going everywhere when I started on the project so I have no knowledge of the previous arrangement.
Is that the OEM connection location, the bottom of the choke heater tube?  I assume I can attach the vacuum hose to any post throttle blade source, but can I leave the bottom of the choke heater tube open?

End goal is to clean up the engine bay and get rid of the emissions parts; keep the PCV and the fuel system vent/fume control.

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Hurley Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Aug/29/2011 Location: NC Status: Offline Points: 197	Post Options Post Reply Quote Hurley Report Post Thanks(0) Quote Reply Topic: Vacuum source for heater control valve Posted: Feb/27/2019 at 5:17pm
	Working on my dad's 2nd 77 Gremlin, this one a bone stock 232 with AC. I've removed the air injection system and the two thermostatic vacuum switches from the side of the block. During this modification, I came across the heater control valve vacuum hose...and what I'm guessing is its source connection - a J-Shaped hard line. It 'appears' to fit in the choke heater tube that protrudes from the bottom of the exhaust manifold.There's no retention on the tube when installed, and of course it was zip-tied to a conglomeration of tee'd and plugged vacuum hoses that ended up going everywhere when I started on the project so I have no knowledge of the previous arrangement. Is that the OEM connection location, the bottom of the choke heater tube? I assume I can attach the vacuum hose to any post throttle blade source, but can I leave the bottom of the choke heater tube open? End goal is to clean up the engine bay and get rid of the emissions parts; keep the PCV and the fuel system vent/fume control.
	67 Rambler American - "The Golden Girl"

knightflight Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Nut Joined: Jan/30/2014 Location: Nor. Calif. Status: Offline Points: 435	Post Options Post Reply Quote knightflight Report Post Thanks(0) Quote Reply Posted: Mar/10/2019 at 8:18pm
	I think you might be confused here.. The tube you are showing appears to be the choke heater, it has nothing to do with the heater valve control. I don't know why it has a check valve on it. Obviously it has been messed with over the years. that needs to come off. The actual choke heater pipe goes from the exhaust manifold to the choke. There may be a second one going from the manifold to the air cleaner area to pick up "clean air' for the choke. The pic you show isn't clear where everything is, but it looks like you have the one for the choke housing. The heater valve vacuum should not go directly to engine vacuum. An engine vacuum hose goes through the firewall and connects to the heater selector, which then, in turn sends the vacuum to the valve when you select the heater on/off. Walt Edited by knightflight - Mar/10/2019 at 8:39pm
	'68 Rebel SST coupe. (X2) '69 SC/Rambler (#7 on registry) '69 Javelin SST Go-Pak 390-4 speed '70 Rebel Machine 4spd '72 Javelin AMX 360 ram-air

Hurley Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Aug/29/2011 Location: NC Status: Offline Points: 197	Post Options Post Reply Quote Hurley Report Post Thanks(0) Quote Reply Posted: Mar/11/2019 at 11:59am
	You can clearly see the choke heater tube attached to the carburetor in the picture; as you said, it goes from the tube in the top of the manifold, over and around to the choke housing. Yes, the vacuum hose in the picture with the check valve goes through the firewall to the heater selector switch first, obviously, then out and back over to the heater valve.
	67 Rambler American - "The Golden Girl"