first of all id like to say i DID do a search. what i came up with is 101 ways to remove smog stuff on TPI cars. nothing on the older carbed 3rdgens. i know how you guys hate repeat topics, but i really couldnt find anything. with that said...

im working on a 84' Z28 with the LG4/auto combo. im in the middle of R&R on the water pump, and since my A/C wasnt working i decided to ditch it while i was in there. i also decided since i was already in this deep, i should ditch the smog crap as well.

now there are quite a few vacuum hoses going to and from all the smog equipment. its a bit overwhelming to see that much emmissions crap! while im sure i could eventually figure all of it out, if i get into a jam i thought id ask you guys which ones i should throw out and which ones i need to keep. im not used to working on these "older" 3rdgens... TPI is more my cup of tea. so here are my questions:

1) what vac hoses do i need to keep intact (im keeping the ECM and all its functions)

2) what size plugs do i need to plug the AIR holes in the exhaust manifolds? (yeah, i know i should get non-AIR headers... it would make thinigs a whole lot easier, but i dont have the money for them right now)

3) it looks as though there is a vac port on the thermostat housing... what is this for and how does it work? i wouldnt think there would be a vac source coming from the Tstat housing!

thanks for looking guys

 

About all you're really going to remove is the air injection reaction system (A.I.R.), aka "smog pump" and associated plumbing. The vacuum hoses associated with its diverter valve can simply be plugged. All you're going to accomplish by doing this is clean up the engine compartment a little, you won't be changing the power output any.

When you remove the tubes from the manifolds, take them to the hardware store to match them for the plugs. That's what 90% of us do, rather than researching what size is needed and getting the parts "to spec".

The vacuum part on the thermostat housing is a vacuum thermal switch. It reroutes vacuum based on engine temp. There should be a vacuum routing diagram somewhere under the hood that identifies these things (one I know is for the EFE valve, which means "early fuel evaporation" that runs the exhaust heat riser valve, as we used to call it).