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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: eventhorizon66 on April 21, 2008, 06:38:08 pm

Title: Thermostatic switch
Post by: eventhorizon66 on April 21, 2008, 06:38:08 pm

I was just curious.  Is it necessary/best to run a thermostatic switch on the vacuum line that runs from the purge control valve of the EVAP canister to the ported vacuum?  I am not running any other form of emissions equipment that would require one.

Title: Re: Thermostatic switch
Post by: VileZambonie on April 21, 2008, 08:28:02 pm

(http://i6.photobucket.com/albums/y228/Sabaka454/evap.gif)

Title: Re: Thermostatic switch
Post by: eventhorizon66 on April 22, 2008, 02:03:37 pm

So that's a yes?  OK, to be clear, which of my first two attached pics is the correct valve?  Based on the diagram, I'm leaning toward the first one.  If so are the hookup labels in my third attached pic correct?

Title: Re: Thermostatic switch
Post by: choptop on April 22, 2008, 05:03:17 pm

That hurts my head :'(

Title: Re: Thermostatic switch
Post by: Fordeatinz71 on April 22, 2008, 05:10:00 pm

yea, mine too.  my truck is gonna be "mostly" original, but i'm simplifying that vacuum diagram.  that's a bunch of garbage.  i will have vacuum for the bare essentials and that's about it...

Title: Re: Thermostatic switch
Post by: eventhorizon66 on April 29, 2008, 03:12:15 pm

Bump.  Hey Vile, is my vacuum hookup (third attachment above) correct or am I looking at the diagram backwards?

Title: Re: Thermostatic switch
Post by: Lt.Del on April 29, 2008, 04:01:46 pm

see if this spins your head around...

(http://www.delbridge.net/tvs45.jpg)

Title: Re: Thermostatic switch
Post by: eventhorizon66 on April 29, 2008, 06:06:41 pm

It looks like the fitting your holding in the pic is for the spark advance/EFE.  I'm interested in the one that regulates the EVAP canister/EGR valve, which appears to be the one mounted directly in the manifold.  My valve for '81-up trucks is different from yours.  But thanks nonetheless, Sarge.