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1978 Wagoneer California emissions vacuum diagram

Posted: Fri Jun 11, 2021 12:02 pm
by Roz
Good afternoon. I am new here and just bought a 78 Waggy. However, I cannot find (because it is no longer on the air filter) the proper emissions vacuum diagram. I have seen the one on olijeep, but it is not from a 78. Would you be able to possibly give assistance?

Re: 1978 Wagoneer California emissions vacuum diagram

Posted: Fri Jun 11, 2021 2:26 pm
by tgreese
The complete '78 TSM is on that site. Look at section 1A for the applicable systems. Then go to each section in the manual for vacuum plumbing. It's not complicated enough to have an overall diagram, like later years.

Looks like there's no California-only spec for the Wagoneer in '78. Vehicles above 6000 lb GVWR have different rules, and likely escaped special treatment in California for that year.

Note that requirements and equipment were changing rapidly in this era, and what was required in other years is not relevant. Use the '78 TSM.

Re: 1978 Wagoneer California emissions vacuum diagram

Posted: Sat Jun 12, 2021 7:51 am
by tgreese
I would also mention - the TSMs are printed in advance of the model-year release, and things might change by the time the Jeeps get to the dealerships. The TSMs also can be mistaken. They are the single most accurate and authoritative source for your year and model, but mistakes are not unknown. I would let the Jeep determine the required emissions systems, if it disagreed with the manual. If your Jeep has vapor recovery, for instance, I would keep it and expect the inspection station will look for it. Same with a cat. I would not remove any systems the TSM says should not be present - that's probably wrong.

First post - welcome from Boston!

Re: 1978 Wagoneer California emissions vacuum diagram

Posted: Sat Jun 12, 2021 7:58 am
by Triumph215
Welcome !
I have a '77 with everything intact and am in Monterey. If you're close enough you are more than welcome to come have a look at how mine is plumbed. I can't yet figure out how to post pictures since I don't use the social media apps and Tapatalk insists that i do. I can email pics to you though if you want to PM me an email address.

Re: 1978 Wagoneer California emissions vacuum diagram

Posted: Sat Jun 12, 2021 9:31 am
by letank
Welcome from the bay area, you should have a sticker on the valence, above the driver's side headlight, under the hood by the coolant expansion tank.

The schematics have quirks... the TSM is a bit lame as there is not a global layout for the whole vacuum system, each unit has a separate description.

Here is the valence sticker for the 85, with the V8

Image

pm if you are around SF, we can help you

Re: 1978 Wagoneer California emissions vacuum diagram

Posted: Sat Jun 12, 2021 10:12 am
by tgreese
Skeptical that a '78 will have a valence sticker with a diagram. It should have a valence sticker with the tune-up information and emissions-related specs, like model, displacement and equipment. Any sticker on the air cleaner would have been only about air cleaner servicing, I believe.

Typical valence sticker from my '82:

Image

Air cleaner sticker:

Image

If you really need a diagram, look at this diagram posted for a 1979 on the Tom Collins site: https://oljeep.com/gw/vac/79/79-FSJ-360_Vacuum.jpg

It will have the same layout for the devices and plumbing, except (according to the '78 TSM) there will be no vapor recovery ("purged vapors") connection.

Re: 1978 Wagoneer California emissions vacuum diagram

Posted: Wed Jun 16, 2021 5:46 am
by Roz
Thank you everyone for the welcome and assistance! I really appreciate the info!!