1974 Postal Jeep Emissions Systems

Hello! I recently bought a 1974 Jeep DJ5C as my daily driver, crazy right? It is equipped with an AMC 232 and Torque-flight 727 transmission, and from my incredibly inexperienced perspective it seems to be running pretty well. This is the first automobile I have ever worked on, so please excuse my lack of knowledge (and thanks in advance for any help!). Any advice anyone can offer on what to check/replace would also be incredibly helpful.

 

So far I have:

 

Replaced a cracked and worn crankcase breather hose (cleaned the breather filter, since I couldn't find copper gauze locally)

 

Replaced the PCV valve and its grommet.

 

Changed the oil, oil filter, air filter and fuel filter.

 

That’s it!

 

What I have now realized is that the PO did not have the emissions system hooked up at all, so I am now trying to figure out how to hook all this stuff up properly.

 

Here are some photos to better illustrate my situation:

 

Overview

 

Vapor canister

 

Carburetor (the PO had plugged the lower port)

 

I am planning on replacing the vapor canister with a new one following this write-up on the Full Size Jeep Forum ( http://www.ifsja.org/forums/vb/showthread.php?t=106051 - http://www.ifsja.org/forums/vb/showthread.php?t=106051)

 

While the vapor canister is labeled with what to plug in from where, I don’t know for sure where all the those bits are.

 

PCV: I know that the PCV will come from a T connection at the PCV valve, and I am pretty sure the other side of the PCV plugs into the Carburetor, but I don’t know if it’s the upper or lower port.

 

Fuel: This is the only line that is hooked up currently, and an easy one to figure out anyways.

 

Ported Vac: I'm pretty sure that this connects to the carburetor as well, but I am not positive since the carb appears to only have two ports.

 

Carb: Since the carburetor only has two ports I have no clue where to hook this up.

 

If anyone can tell me what these ports are, or offer any other advice about where to connect my vacuum lines, I would be very grateful!

Edited by mentalfrosting - Feb/23/2015 at 1:31pm

The best way to hook this stuff up is to just get a factory service manual for it. Trying to describe this stuff over the internet is pretty pointless. Manuals are cheap on ebay. Chilton's or Haynes are worthless, you need the actual factory service manual.

Needless to say, the upper (large) fitting on the carb goes to a small tube on the underside of the exhaust manifold. The upper end of this tube comes out the top of the manifold near the carburetor and routes to the choke. If that system is messed up the choke will not open properly and it will run like crap at best. It will also suck in dirty air and ruin the carburetor.

The lower vacuum fitting goes to a the CTO switch screwed into the side of the block under the manifold. Another line from direct manifold vacuum also goes to this same switch, then a third line goes from the switch to the distributor advance.

There is a 2" diameter circle on the underside of the air cleaner snorkel. There is another matching one on the side of the exhaust manifold. A flexible preheater hose is supposed to connect the two so the carburetor gets warmed in cold weather. You need that to run properly in cold weather.

PCV valve in the back of the valve cover should have a 3/8" hose connecting it to a fitting on the side of the intake manifold, below the carburetor. The other hose at the front of the valve cover that goes to the air cleaner should have a mesh filter that is accessed through the air cleaner. Keep the filter clean and lightly oiled.



Edited by FSJunkie - Feb/23/2015 at 3:55pm

The $45 for the service manual is the "part" you need now.
You stated "excuse my lack of knowledge"
Get your knowledge from the manual.
Why just change parts for the sake of changing parts?
Ollie

You have to remember, when the postal service had it, it did not have to go through an emission test. Years ago even the postal truck drivers didnt even have to have a drivers licence, they had to have a government licence.

purple72Gremlin wrote: You have to remember, when the postal service had it, it did not have to go through an emission test. Years ago even the postal truck drivers didnt even have to have a drivers licence, they had to have a government licence.