Air cleaner trap doors

[brielly]

Since the weather around here has been sooo cold my weber carb never really warms up. Ive decided to adapt the original carter air cleaner to the weber to get it to warm up faster but I'm not too clear on setting up the vacuum lines to run the trap doors. It looks like the original ran from ported vacuum from the carter so I'm assuming I need ported vac from the weber. There is one ported vac hose currently running from the weber to the canister purge signal. Can I put a tee on this hose and connect the lines to run the trap doors? Or would putting a tee in take vacuum away from the purge signal and not be enough to run both? I'm not real schooled on vaccum lines and tees, etc so any help or suggestions would be appreciated. Thanks!

[carrotman]

I've read that the newer Jeeps have two "trap doors" on them. If yours has only one, it's probably like my 76. It has a full manifold vacuum line to a heat sensor on the bottom of the air cleaner. Another vacuum line goes from the passenger's side of the heat sensor to the trap door. The door should be closed when the engine is cold, and should open to outside air when warm. If the sensor doesn't work, you can get a new one. Make sure the aluminum/paper tube is hooked up to the little stove on the exhaust and to the bottom of the trap door.

[carrotman]

I've read that the newer Jeeps have two "trap doors" on them. If yours has only one, it's probably like my 76. It has a full manifold vacuum line to a heat sensor on the bottom of the air cleaner. Another vacuum line goes from the passenger's side of the heat sensor to the trap door. The door should be closed when the engine is cold, and should open to outside air when warm. If the sensor doesn't work, you can get a new one. Make sure the aluminum/paper tube is hooked up to the little stove on the exhaust and to the bottom of the trap door.

[brielly]

Mine has the two trap doors. One should open when the truck starts and the other when the sensor detects that its warm enough. I may have to try both ported and manifold since Ive read and seen conflicting info online and in manuals. The real question I have is can I run a tee into other vacuum lines or would that cause there to be less vacuum to other components?

[nograin]

it doesn't make any sense for them to be using ported vacuum. the only thing that needs ported vacuum is the distributor on emmissions controled vehicles (like your 83).

Port vacuum provides now vacuum at idle. The outer vapor door and the heat control flapper both bull from the same vacuum point on my v-8. I don't have diagram for an 83 6, but the concept is the same. On the 8 they pull right from a manifold runner, but it can be from anywhere. There is little flow in the vacuum lines (they all dead end) so yes you can T and multiple T with no adverse effect on the vacuum reading.

There is a check valve and/or delay associated with the flapper 'motors'. However I think you can get started and add them later as you find 'em. Junk yard, dealer, or specialty dealer would be my suggestions for those.

[sloop]

I agree with nograin, use manifold vacuum not ported. There should be a delay valve on the main trap door line.

I am not sure which valve you use to control the heated air duct motor.. perhaps the CTO and one of the temp sensors in the air cleaner? I can try to find a vacuum diagram for you.

[Bob Barry]

FWIW, the vacuum delay valve for the snorkel flappers is a REVERSE delay valve, to prevent those flaps from closing up when you get on the throttle (and the vacuum drops). They keep the vacuum in the lines to the door motors for a while.