Posted by T.L. on February 05, 1999 at 01:01:21:
In Reply to: Re: help with vacuum line(s). posted by Ron S. on February 04, 1999 at 18:07:44:
...I forgot about the vacuum tree in the back. When I put the Edelbrock on , I removed all that stuff...
: 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.
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: : '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?