BBD carb vacuum ports on the 258

[MDJEEPER]

Guys,

I am trying to figure out what should be connected to the vacuum ports on the BBD carb. Although the PO hacked up stuff, the computer is still currently connected. But, I am not convinced that the vaccum advance for the distributor and the EGR valve are connected in the right places. Where should they be connected?? It looks like I have the following ports available:

1. front left of the carb (does not seem to have vacuum at idle??)

2. middle right side of carb (this one I think is ported)

3. back left side of carb (has vacuum at idle)

I am still trying to figure out why my AMC 258 i6 / 4.2l still has knocking/pinging. The timing is set right according to specs, so I am now looking at the vacuum system...

Which ports do you think the vacuum advance and the EGR should be connected to??

 

[dslywalker]

Try this one.If its a blank pic click on it anyway it should open
Mike

 

[MDJEEPER]

Thanks! Part of the problem I have having is that a lot of this stuff just isn't present on my project. So, right now the PO has the vacuum advance connected to the front port on the left side of the carb (front right side if you are looking on under the hood). As I am looking at this diagram, it looks like that port is capped off.

The PO also has the EGR valve connected to the charcoal canister.

Because I do not have the parts where these things are connected according to the diagram, I am trying to figure out where they should go...

 

[MDJEEPER]

Oh, I also forgot...Since it appears that the port where the vacuum advance is currently connected is not doing anything, is my knocking/pinging problem under acceleration actually going to get worse if I connect it to manifold vacuum (like what the diagram seems to indicate)? Or, because the computer is controlling it, the standard ideas about vacuum advance don't apply??

I apologize if I am asking a stupid question!

 

[dslywalker]

Search thru this link theirs a bunch of info
Table of Contents

 

[dslywalker]

Here's a pretty basic vacumn schematic.Hopefully someone will come along with more knowledge on this style of vacumn.
Mike

 

[MDJEEPER]

Here's a pretty basic vacumn schematic.Hopefully someone will come along with more knowledge on this style of vacumn.
Mike

Thanks!

We definitely have to throw out the manual on this one! The knowledge and wisdom of the forum members will be greatly appreciated!!

 

[Golden CJ]

I can't use the search box! and I didn't find any place better than here,to ask my question; dear jeepers what is the difference between these many!!! vacuum diagrams? I mean if I use my egr like this and another friend like that above ^
what will happen to mine and to the friend's?

 

[mtnwhlr]

I can't use the search box! and I didn't find any place better than here,to ask my question; dear jeepers what is the difference between these many!!! vacuum diagrams? I mean if I use my egr like this and another friend like that above ^
what will happen to mine and to the friend's?

The one above is for a Howell TBI setup the one in your post is the stock setup

 

[Golden CJ]

The one above is for a Howell TBI setup the one in your post is the stock setup

I saw another with 2 other valves?!

 

[alpha6]

Not sure it will help, but on my build forum, I took some pics of the vacuum set up as I was changing out my carter... http://www.jeep-cj.com/forums/f98/rocky-mountain-85-cj7-16192/index6.html