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Unread 09-07-2014, 01:00 PM   #1
Leadmine
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1979 CJ5 
 
Join Date: Aug 2014
Location: jackson, ky
Posts: 117
Vacuum system on 304 is a MESS!

Been searching this forum and googling all morning and its just left me more confused than I was. I bought a really nice specimen of a CJ5 recently after looking for several years. Its obviously been well cared for and has some high dollar parts but I guess the last owner did a little cobblin'. Anyway, I ordered a CD of the original 79 dealer service manual and have been using that to correct all the crap the previous owner hacked. Got to the engine's vacuum system and have hit a snag. I'm getting a small amount of vapor coming back through the oil filler cap, which I've read could be cause by a bad PCV valve. Printed off the "49-State 304/manual trans - CJ Models" vac diagram from the cd. Checked it and both ends of the pcv were plugged with screws. upon further inspection I noticed a couple things.

1. The air pump, diverter valve, non-linear valve and egr cto switch are GONE.
2. Distributor vac line goes straight to the back of the carb, instead of to non-linear valve as shown in the diagram. The rear port of the carb is where the PCV is supposed to run to, according to diagram.
3. Diagram shows a rear port for PCV. Also shows an "E" port coming off the front that is supposed to be capped, and a "S" port on the passeneger side that connects to all the missing stuff. My carb doesnt have E or S port. Its a motorcraft and I believe its the original carb but I could be wrong.
4. evap canister has one green plastic hose that comes off and runs back toward the gas tank, neither of the other two nipples are hooked up.
5. EGR valve isn't hooked up to anything or capped.

SO......my big question is the PCV. If I hook it up as shown in the diagram where can I get vacuum for the distributor? Can I put a T in the line and hook them both to the same port? I just put in a new rear main and pan gasket (pan gasket was pouring oil). Engine doesn't leak a drop now, runs great and I'd like to keep it that way. Its obviously not too affected by the missing parts I just want to make sure I'm not missing something that is needed or will cause problems down the road. Any advice is greatly appreciated.

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1979 CJ-5 Chevy Hugger Orange paint, 304/T-18/Dana20 on 15x10 old school Welds with 33x12.5s
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Unread 09-08-2014, 04:56 AM   #2
AZ_Chip
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1978 CJ7 
 
Join Date: Jun 2014
Location: Mesa, AZ
Posts: 376
Hi,

Which carb do you have? I have a AMC360 in my CJ7 and the vacuum lines have been a real bear to get sorted.
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Unread 09-08-2014, 05:52 AM   #3
Leadmine
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1979 CJ5 
 
Join Date: Aug 2014
Location: jackson, ky
Posts: 117
I have (according the my service manual) a Motorcraft 2100. I went back and read through everything I could find on that carb and it doesn't explain much about where to pull vacuum from. The vacuum diagram my service manual shows for my engine doesn't match up to the vacuum ports on the carb.

On a side note, the cto switch
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1979 CJ-5 Chevy Hugger Orange paint, 304/T-18/Dana20 on 15x10 old school Welds with 33x12.5s
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