Posted by T.L. on February 08, 1999 at 22:40:50:
In Reply to: Hey T.L. posted by TParker on February 08, 1999 at 18:45:25:
Believe it or not, the warm air setup was not designed to help your engine "warm up" faster on cold mornings. It is an emmission control device. When the engine is cold, it needs a richer air/fuel mixture to keep it running. especially on a cold day. Translation: more pollution. This setup routes heated air (flowing past the exhaust manifold) into the carburetor for better fuel atomization and a more complete burn. Once the engine reaches operating tempurature, warm air is no longer necessary and the "fresh air" passage opens . I removed all that stuff and my car runs great (in cold Colorado!) and it's MUCH easier to change spark plugs without that "heat stove" in the way. I even removed the choke on my Holley carburetor and don't use a choke. I do however need to keep my foot on the gas pedal until it warms up a bit but I don't mind. People don't realize that more often than not, warmup problems with these cars are caused by a choke closed too much OR not opening soon enough. Give that car come AIR...
: T.L. with the open air cleaner and all of the warm air stuff removed isn't it a bitch to start and keep it running on cold mornings in Colorado? I was just wondering, cuz I have fresh air induction(in front of the radiator) with a sealed air cleaner(no warm air snorkle) on mine for the HOT summer day's here in SoCal, but some times in the winter it's hard to keep running after the choke opens up until the engine is up to 180deg. then it run's fine.
: : ...I forgot about the vacuum tree in the back. When I put the Edelbrock on , I removed all that stuff...
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: : : The heated air valve in the snorkel requires vacuum to CLOSE not to open, it should "rest" (no vacuum applied) in the open state. The source of vacuum to the thermostatic switch is directly from the vacuun "tree" on the intake behind the carb (it may be routed through a small plastic connector on the air cleaner assy). The line should run from the tree to the switch then from the switch to the snorkel.(My reference is the 1973 Ford Service Manual Vol. 6 'Engine and Emission Sytems Diagrams' ... II'll 'Snail' mail you a copy of the page if you like). The 3 outlet 'valve' (Ported Vacuum Switch=PVS) IS to control dist advance (in the event the engine begins to run hot, this valve 'opens' and applies manifold vacuum to the advance to raise the idle speed of the engine). The 2 outlet 'valve' (Temp Controlled Vacuum Valve=TCV) is for EGR control (and trans Modulator vacuum on some cars) allowing it to be "active" only after the engine is at operating temperature.
: : :
: : : : '73 v8 302. Have Chilton.
: : : : Problem: there is no vacuum line coming off of the bimetal sensor in the breather that actvates the door in the snorkel to allow heated air into the breather. I'm pretty sure it won't open without a vacuum source.
: : : : The only reference I have found shows the hose exiting the breather, and states "to vacuum source". I have hunted and dont see any unused ports or capped hoses, other than the EGR which I did.
: : : : Question: where should I route the other end of this line? Didn't ford have a specific connection?