trøy

Anyone know if the VSV's can be swapped around or are they each doing something specific?

I am trying to piece back together the emissions for an 81 CA 4x4 model which has ~8 VSVs.

Are they all the same? Universal?

Any help on this is much appreciated.


(Meant vacuum switching valve)

L5wolvesf

Some, if not all, of the vac devices have a part number on them. Do yours?

trøy

Unfortunately I don't have any whatsoever to go off of to know the correct part number. They were stripped out of my truck before I bought it and I am trying to get it smogged in CA.
I found a bunch online (eBay) and have been to a number of junk yards to get them from 81 specific trucks as that year and ca model has the most vsv's.

millball

Most of the VSVs on the trucks I have; have plugs that are unique to each VSV, so that they cannot be easily interchanged even if their function might be the same.

rickc5

I pulled most (if not all) of those valves off my '83 when I de-smogged it. Several broke off due to the plastic getting so brittle after 35 years. Those that broke looked all plugged up with funky stuff too, so I doubt they even were doing what they were designed to do. I only mention this because I would think that any of the old, original valves would also be suspect.

So unfortunate that Kalifornia requires all that (useless) junk be attached to the engine regardless if it still works or not. BTW- with all the smog junk on it, my 22R ran terribly--way too rich & not adjustable. Now that I have a new Weber and no useless smog junk, it runs great and gets much better gas mileage.

Best of luck getting your truck to pass the smog inspection.

L5wolvesf

This might help. It is for my 84 but you should be able to find your truck on this site.
https://www.toyotapartsdeal.com/part...BU;0=RN50L-KRA)

Also, some of the emissions devices are actually helpful in making the engine run more efficiently. Specifically I thinking the charcoal canister and the High Altitude Compensator.

old87yota

^^ Yes.

Actually, the emissions systems are not useless. Toyota did not design a stripped down engine and just threw a bunch of "emissions junk" after the fact to make the numbers work.

Toyota carefully thought through what they were designing.

The way they accomplished meeting emissions standards was through improving carburetor driveability and efficiency. Many of the emissions systems first aimed to improve how the engine ran under a variety of conditions. The better that Toyota could get the engine to run, the less emissions the engine produced.

When vacuum switching valves and other things stop working is when people have problems with emissions systems (duh, right?). The problem is not the emissions systems, but a failure of the emissions systems.

Unfortunately, I do not have any ~1981 trucks or parts to compare to.

Good luck!