304 V8 fuel and vac lines underhood

[mrhc]

I am trying to re-connect all the lines to the intake manifold and carb and charcoal canister. I have yet to find a pic that has the same connections on the intake as my 79 CJ-7. Its a 304 and it seems that none of the pictures I have found have the same intake manifold or carb. Really confused. The pictures here show the three places that I'm not sure what connects to it. Each of them are on the front of the manifold. The one carb pic is where I think the charcoal canister connects. Also the CC has a place marked for the distr. vac, what connects here? Have I mentioned that I'm confused? Any help would be appreciated.

 

[greg92jeepxj]

I am currently waiting for a reprint 1980 AMC jeep shop manual from Willys overland and hope to see it soon as many questions arise of this nature requiring a manual to dope it out . Hope to get it soon , if you do not have an answer by then , will help from manual . Will try to find anything else I have that may be helpful with emissions controls , thanks for supplying the year , make and engine.

 

[69jeepcj]

Not positive, but will check my manual in a minute. In the first pic im not sure if you are referring to what looks like the thermostat housing or the threaded hole in the manifold. If the thermo housing, your temp sending unit will go there, no vac lines will go there. If your referring to the threaded hole in the intake, im not sure what that's for, I have never seen anything connected to that spot, Always has a bung in it. Second pic is where I think your charcoal hose will go (I double check that). The carb pic looks like the fuel inlet, or a vac port for power brakes, EGR valve...it looks too big for the vac advance hose. I have to work this morning so it may be later before I can post. Is your manifold stock?? can you post a pic of the whole manifold and the whole carb?

 

[PoliceMonkey161]

I am trying to re-connect all the lines to the intake manifold and carb and charcoal canister. I have yet to find a pic that has the same connections on the intake as my 79 CJ-7. Its a 304 and it seems that none of the pictures I have found have the same intake manifold or carb. Really confused. The pictures here show the three places that I'm not sure what connects to it. Each of them are on the front of the manifold. The one carb pic is where I think the charcoal canister connects. Also the CC has a place marked for the distr. vac, what connects here? Have I mentioned that I'm confused? Any help would be appreciated.

At a glance, you are correct about the carb. port going to the cansiter. The nipple on the CTO valve marked "distr. vac" gets tee'd into the ported (not full) vac line, which runs from the small nipple just above the throttle plates at the base of the carb. If you follow the hose your teeing into, it's connected to the dist. vaccum pot.


The third photo (or second in order), I'll need to think about????? Maybe it's just the photo, but it seems out of place? But in the meantime, someone else may have input. Keep in mind that regardless of a 4,6 or 8 cylinder, the emissions controls have the same amount of plumbing. They're just located in different places.


I have to ask, a 79 CJ7 would not have had any emissions control equipment, why are you hooking it up for your resto/mod? Is it required by the state your in?


John

 

[PoliceMonkey161]

I see 69jeepCJ and I are on the same schedule....... In certain circles, I would say" Jinx-you own me a Coke". As he stated, the first photo is were the temp probe goes (I knew something was bothering me about these photos). So where is your temp probe at now? You may need to switch thier postions. Take a look at the diagrapm there:


It comes down to you have two seperate CTO valves and the diagram show the single, four port valve used on later 6 cylinder engine (from 84-90' I believe). Regardless, consider you still have four ports. So could look at it by drawing a line (vertically) down between the four ports in the diagram.


Although, 69Jeep brings up a good point about the nipples on the one valve look large?

 

[69jeepcj]

I think 79 only had the charcoal canister and a few metal tubes connected to the exhaust manifold. Every jeep I have gotten has already had that stuff taken off. I checked my manual and in you first pic of that threaded hole in the manifold, that is for a A/C bracket. Im glad policemonkey knew what the others were for.

 

[mrhc]

Thanks for the help. I will have to digest all this info and get some pics of the manifold and carb. The carb is a Motorcraft 2150. I was just trying to set it up the way it was before I took everything apart is why I'm connecting all the emissions stuff. And, of course, I didn't take any pics before I took it apart. I will be home later and will get some pics uploaded.

 

[mrhc]

The first pic is the connector on the back of the thermostat housing. It seems that every diagram I see has something different attached here. The second pic is a three pronged connection that is attached directly to the manifold. The one hose connected here is the EGR. Don't know if that is right. Ok, here's my ignorance showing, what is a ported vac? And thanks.

 

[PoliceMonkey161]

First photo: The CTO that is in your thermo housing needs to move to a thread port on the intake manifold. The temp probe will go in its place.


Second photo: The CTO valves can be interchanged, a CTO is a CTO other than the barb/nipple size. They are just thremo switches that control airflow (well vacuum in this case). So one side/nipple goes directly to EGR valve and the other nipple will tee into one of the nipples on the second CTO and then tee into the ported vacuum line between the carb and distr.


I know it sounds complex, but try working just one nipple at a time.....It will start coming together for you.

 

[PoliceMonkey161]

"The second pic is a three pronged connection that is attached directly to the manifold."

Sorry, missed this the first time!So, I see how this is confusing. If the bottom (large hose) is connected to the bottom of the valve and runs to the manifold (it would have to be threaded barb just below the carb adp.?), this is "Full Vacuum" which will still work. One of the other two nipples/lines goes to the EGR and the other goes to one of the nipples on the other CTO. Just think of it as a built in tee.


Ultimately, after startup, you may want to re-plumb it so you are using only ported vacuum if you start having low idle problems.

​

 

[greg92jeepxj]

I sure appreciate the assistance and advise of fellow members 69jeepcj and policemonkey161 as they are experienced jeep owners whom currently drive the same or similar vehicles . My reference manuals are coming up short on proper vacuum diagrams for this jeep and my order of a 1980 AMC shop manual will not reach us soon enough to help. Yes , it would be good to see the intake and know what emmissions equipment that will be used for emmissions compliance .
I could help with what knowledge I have of these emmissions systems , but if its better to go with the book for accuracy for this vehicle to be period correct for compliance purposes , then I guess the posted diagram and both 69jeepcj and policemonkey161 can reference best from their jeeps and most likely have best reference to them than I currently have. I know when I did my vacuum lines on my previously owned '78 cherokee 360 , I just swapped it line by line. Sorry that wont help now. If its being questioned about the large nipple on the air horn , that is to feed vapor to the float bowl from the canister to burn in engine off -idle when vacuum motor on canister receives vacuum signal off-idle and the vacuum is routed through a thermal vacuum switch , actually called CTO for this jeeps purposes . I believe the distributor shares the same vacuum signal from the carburators float bowl , not throttle body for off-idle response but the distributor will not go to CTO as it does not need to be temperature controlled until engine is warm unlike EGR and CHARCOAL CANISTER do. I think that should be key , what is needed to work after engine is warm and what can work before so. Distributor signal , no CTO but off idle signal , EGR and CANISTER , CTO from off-idle signal port. Throttle body(lower carb) signal present at idle only , lost after acceleration . Float bowl(upper carb) signal gained after acceptation . Will need vacuum advance above idle and EGR and CANISTER enrichment only after acceleration . The EGR signal is metered by CTO and the CANISTER signal metered by CTO and vacuum motor. Naturally it is important that all be routed correctly and hoping 69jeepcj and policemonkey161 ' s jeeps and personal reference can properly sort as it is taking long to get my shop manual from Willys overland . With regards to the thermal vacuum switches , if one were placed in thermostat housing , that would only supply vacuum with warm engine , and if the other in intake , that would supply constant but stronger above idle signal for CTO , but still we need the correct routing for correct operation ? That's really all I know and is basic , I know you guys have the best reference available , your jeeps ! Wish I could be of more real world help to positively identify , but the jeeps and their owners know better than me ! LOL ! Best of luck and hope my post is more helpful to you all and less confusing as well . Hope my post digest well and does not give indigestion ! Double LOL !

 

[mrhc]

Ok, here are some wider pics of the manifold where these connections are located. A lot of what you have all suggested is very helpful. I will be trying to go connection by connection and see if I can't get everything hooked up properly.

 

[PoliceMonkey161]

Ok.....I need to cut back on the crack! I looked in my Chiltons manual this evening and I (and we for that matter) made some incorrrect assumptions. First off, the one CTO valve in the thermo housing is correct (however I believe from the diagram below, its the wrong one in there currently?) I scanned a couple of diagrams for you:





This should help you. I honestly have little experience with AMC V-8's. But as I stated earlier, Emissions systems have the same componets regards of engine size, they're just in different locations. Much to my surprise the pre 80's era layout is far different than the post 80's.


I would recommend getting a copy of the Chilton's manual from your local auto store. In comparision, Chilton's go into more detail about this subject better than Hayes.

 

[PoliceMonkey161]

Hey, I didn't notice your newer photos, you have the CTO's in the right places.Look at the new photos, you've done a fantastic job on the motor. I would thing all your going to need is to just re-connect each vacuum line at a time?

 

[greg92jeepxj]

Hey guys , just had a look at the manual posted , thank you policemonkey161 , I won't get my reprint until next week from Willys overland , but yeah , the thermal vacuums switches , I mean , CTO's look right if I understand what they mean by non-linear valve , should be right , then it should be plug and play ! But that are both thermal controlled , so they will do the same job , open when engine warm. Just a matter of the vacuum source going to the vacuum port on switch and the EGR and canister will be on the thermal controlled ports . Forgot to ask , but I guess the fuel pump is not vented . Really nice job on the engine ! I can hardly wait for it to be started too ! 69jeepcj mentioned the tubes on exhaust , is this engine supposed to have the air injection pump ? The manual is not illustrating one .

 

[mrhc]

There is not an air pump on this engine. Thanks, it has been a long time since I took this thing apart. Just need these hoses connected properly and the wiring harness installed and hopefully it will start!!! Keep your fingers crossed.

 

[greg92jeepxj]

So glad that the emissions equipment is low tech in its simplicity for that year . Makes a restoration easier and just less to burden the engine . I know you'll get it right , I'm sure that even though its been some time since you tore it down , memory will prevail . It just has a way of coming back to you . Special thanks to 69jeepcj and policemonkey161 for lending their experience and expertise through personal ownership of similar models must have helped greatly ! We're all just looking forward to , as you are , the day coming soon that she fires up and drives showroom new ! I remember some pics of your restoration work and I must say , ABSOLUTELY AWESOME ! We await with anticipation of the news , " she's running ! " ! Won't be long !:beer:

 

[greg92jeepxj]

There is not an air pump on this engine. Thanks, it has been a long time since I took this thing apart. Just need these hoses connected properly and the wiring harness installed and hopefully it will start!!! Keep your fingers crossed.

I found this post with this FSM page that showed the CTO's similar to how your 304 is assembled . I don't know if this is useful or correct for your jeep , but It got my attention because of the two CTO set up . Hope this helps as I have nothing in my current library to research from for a 1979 CJ and still awaiting my reprint in the mail. Thanks again to brothers 69jeepcj and policemonkey161 for their dedicated research ! this was from a post for a 1979 CJ 304.

 

[69jeepcj]

Sorry I couldn't help more. Im not sure I have ever seen the 304 with all the emissions and vac lines hooked up from the factory. By the time I get them, the lines, hoses have been cut, blocked off, rerouted and so fourth. That's where sites like this come in handy, you get two, three people working together to try and figure it out.. hope its about ready to fire up!

 

[PoliceMonkey161]

Sorry I couldn't help more. Im not sure I have ever seen the 304 with all the emissions and vac lines hooked up from the factory. By the time I get them, the lines, hoses have been cut, blocked off, rerouted and so fourth. That's where sites like this come in handy, you get two, three people working together to try and figure it out.. hope its about ready to fire up!

Well said.....Sir!