I R/R 4.3 on 95 sonoma and it was months before it went back in.

I thoiught everything in place but keep throwing a P1442 GMC - EVAP Vacuum Sw. High Voltage During Ign. on.

I replaced switch, made sure wires engaged properly and so forth.
there is a vac? port facing down in the switch I cant figure out if atmosphere vent or supposed to be connected to hose.

anyone? just run out to you 4.3 1995 vortec and pop the hood.

driver side
up on top of valve cover to the side of the intake maniolfd.
2 switches with vac lines running into them-they are also conencted together with vac hose.
the REAR switch has 2 ports at teh back and 1 out the front to the other switch.

UNDERNEATH there is a vac nipple facing down

DOES YOURS HAVE HOSE CONNECTED?
if so-where does that hose come from.

if not... back to the drawing board chasing that 1442.
Thanks
Mark

 

http://i1078.photobucket.com/albums/...ps45880f39.jpg

http://i1078.photobucket.com/albums/...ps4f6c69af.jpg I think you have them reversed. The round one for leaded gas is closest to the back {winshield}. Mine only have two vac ports each.

If you have them correct and still getting a code someone might have snapped the front vent line on your gas tank when the fuel pump was done, that's if you have a four door.

 

What I have is DOH syndrome in my descrption.
I have teh exact setup as your picture-i just described them wrong-thanks.

so, my back one is 1 in/out, the front one is 3 in. both with electric connectors.
I have replaced the rear one with brand new part. still the 1442 code.
repaired wires for better conenction at rear switch... still same code.


so on your rear one right under elect conenctor is there a vac nipple hanging down?

 

No there is not. If you go to rockauto they have pics of both parts all around them if you click on the "more info" bar.

Take a look at a pic of your fuel tank. Like I said if it's a four door the front vent nipple always breaks and will toss an evap code. It can be fixed without dropping the tank. Did it on mine and no more code. You can tell if it's broke by feel.