Questions about 78 CJ5 around the carb

[jpeck71]

First let me say that I have a service manual on order and should have it soon, but I thought I'd try to get some help on here. This is my 78 CJ5 . It was a farm vehicle for the last nearly 20 years and things have been disconnected and removed. The Jeep runs, but I'm trying to track down leaks and resolve things to get it running smoother.


This circled fitting below has vacuum on it and is completely open. I can close it off and plan to do that but I'm wondering what it is supposed to be connected to. Its the bottom side of the choke assembly.



This circled tube below is not connected to anything and does not appear to have any suction. I'm not really sure what it is for.


This picture is a little blurry but is of the driver's side of the carburetor just above the EGR valve. The fitting has two tubes coming out of it, one appears to be closed off, the other has vacuum on it. I'm not really sure what that is supposed to be connected to. Currently it has a hose attached that goes through the firewall and appears to be connected to the windshield washer nipple under the dash. That doesn't seem right.


This was connected and when I was trying to disconnect the hose to replace it the whole nipple popped out of the carburetor assembly. Is this normal? It slides back in the hole and I don't think I pulled with enough force to snap that nipple. I was just trying to slide the hose off. The hose connects to the top of the valve cover.



Again, sorry this is blurry, but its a hose that goes through the firewall right above the electrical and next to the brakes. This is the hose that connects to the carburetor and seems to connect to the washer under the dash. Is this supposed to be the washer fluid line? I don't have the washer fluid bottle or the fluid pump anymore.


Some of these things I might learn from my service manual but that won't be till the weekend.

Thanks for any help you can give.

 

[Peanut Butter]

Picture 1 you are missing a metal tube that connectsvthere and to the exhaust manifold to provide heat to the chock.

Picture 3 is a manifold vacuum source.

Not sure what you question is about the washer fluid line. It runs from the washer fluid holding tank through the pump and up through the dash to the outlet.

Rod

 

[Jimbos76cj]

Pic #1 Thats a connection for the choke system if it was set up in the stock formation. looks like you have a manual choke set up now. Cap that opening.. it can cause a small vacuum leak

In the last pic that hose is normally for the wiper sprayer. If its hook to your carb then you have another place for a leak.

In pic number 4 The hose that goes to your valve cover is normally your PVC hose.. I dont think thats the right carb port for that. Honestly with as many open lines as you have Im supprised that it runs. I dont have alot of knowledge about the older CJ6 cyl vauum lines so your book is going to be the best place to look heres a quick run down to figure out what you need off your carb

1) Vacuum hose for the distributor
2) Vacuum hose for your PVC. thats the easiest lest complicated way to set up your motor.

I would think the distributor hose should go to the nipple in pic number 2 with the hose and bolt on it.

The line for the PVC is normaly a big nipple on the bottom of the carb usually on the fire wall side.

Every thing else needs to be capped with THE PROPER CAPS. Most parts stores will sell boxes with multiple size caps. Use the thightest fitting caps you can find. If theres no vacuum on it cap it any way. Some one will chime in and say you need to make sure the purge system is operating properly but looking at the hack job you have bought Id say that system is also chopped up.

That circled part in pic 3 with the one line and other one is open looks like a CTO switch. Normally when the motor heats up it opens allowing vacuum to be applied to what ever its operating through the missing line. If your motor is warm and no pulling vacuum through there Id suspect that it is bad or your heater hoses have been rerouted so coolant does not go through the intake.

Helll while Im throwing my guesses out there pic number 2 I would guess is the line that is supposed to go to the fitting in pic number 1 only if it comes directly off the exhaust manifold. other then that I have no idea.

Good luck with your project.

 

[jpeck71]

Picture 1 you are missing a metal tube that connectsvthere and to the exhaust manifold to provide heat to the chock.

Rod

Ok, that makes sense. This now has a manual choke. I capped it off with a temporary cap. I'll find a better one later.

Picture 3 is a manifold vacuum source.

Not sure what you question is about the washer fluid line. It runs from the washer fluid holding tank through the pump and up through the dash to the outlet.

Ok, I capped this off. My question was just to verify that was the intention of the line going through the firewall. I don't have the washer tank or the pump and this line was connected to the manifold vacuum.

This verifies what I was guessing and I've capped everything off and its running better. My vacuum advance is still not working yet so I'll have to work on that at some point.

Thanks.
Jeremy

 

[jpeck71]

Helll while Im throwing my guesses out there pic number 2 I would guess is the line that is supposed to go to the fitting in pic number 1 only if it comes directly off the exhaust manifold. other then that I have no idea.

Good luck with your project.

Yes, this is going to be interesting. Now that I've capped off a bunch of open lines it is running better. I'll be going through the FSM this weekend trying to make sense of it. There are lots of things removed, windshield washer, exhaust canister and heater are a few.

Thanks for your help. Both of you confirmed the guesses I'd already made.

Jeremy

 

[Jimbos76cj]

Ok, that makes sense. This now has a manual choke. I capped it off with a temporary cap. I'll find a better one later.



Ok, I capped this off. My question was just to verify that was the intention of the line going through the firewall. I don't have the washer tank or the pump and this line was connected to the manifold vacuum.

This verifies what I was guessing and I've capped everything off and its running better. My vacuum advance is still not working yet so I'll have to work on that at some point.

Thanks.
Jeremy

For your vacuum advance make sure the hose is hooked to the right port on the carb. I dont know the proper neame for each port but as I understand it there is 2 types of vavuum sources. One source will have a constant amount of vaccum to it. I think that it called manifold vacuum and then the other source increases and decreases vavuum with engine RPM. You want your distributor to be hooked to the port that increases vacuum with rpms. Normally these are found on the lower portion of the carb. IF your vacuum advance is not working try removing the cap and rotor and line from the advance and try to manually move the advance. If it moves and returns back to where it should that means the mechanism is not stuck. again push the advance lever in but this time cap the advance port with your thumb. If the lever gos right back to where it was you have a bad vacuum advance. If it stays in your advance mechanism is good so you just need to find a good vacuum source for it. Id also replace the vacuum hose for the distributor just incase it has a hole that you cant see.

 

[jpeck71]

You want your distributor to be hooked to the port that increases vacuum with rpms. Normally these are found on the lower portion of the carb.

Makes sense. I'll have to check that once I get my service manual. It's connected to vacuum but I'm not sure which kind yet.

IF your vacuum advance is not working try removing the cap and rotor and line from the advance and try to manually move the advance. If it moves and returns back to where it should that means the mechanism is not stuck. again push the advance lever in but this time cap the advance port with your thumb. If the lever gos right back to where it was you have a bad vacuum advance. If it stays in your advance mechanism is good so you just need to find a good vacuum source for it. Id also replace the vacuum hose for the distributor just incase it has a hole that you cant see.

We did try pushing on the lever and it does move and go back so I don't believe its stuck. I did replace the vacuum line to the distributor so it should be good. I'll try pushing the lever and plugging the port though.

Thanks.