smoke machine for diagnostics

[thistle3585]

So, your comment about the PCV made me think, so I did a bit of a search and found a thread on an AMC website discussing similar symptoms. The long and short of it, I ended up hooking my dizzy to the ported vacuum and plugged the manifold port. I also turned out the idle screws on the carb and the vacuum came up within a tolerable range. I'm going to fiddle a bit more with it but it does look promising. I'm wondering if there should be a line that runs to the valve cover in the hose that runs from the PCV to the carb? I took it out for an hour drive and it ran well. A little backfiring when downshifting but not near as much as it had in the past.

 

[Neuner]

So, your comment about the PCV made me think, so I did a bit of a search and found a thread on an AMC website discussing similar symptoms. The long and short of it, I ended up hooking my dizzy to the ported vacuum and plugged the manifold port. I also turned out the idle screws on the carb and the vacuum came up within a tolerable range.

I think Hedge is on to something.
ed
I know you have the AMC 304 but when I got mine, the PO had the canister completely out of the loop on my AMC 258 i6 / 4.2l with some weird short cut. I was trying to resolve some issues I was having that seemed similar. I'm not too sure on how all of the vacuum systems worked so I did a lot of searching and re-integrated a canister from a 98 ZJ in as simple of a manner as I could, not incorporating the CTO and it took care of the majority of issues.

I'm not saying the canister was or is the solution but the way it made me connect the vacuum to various systems worked.

Don't remember too much about it but I do know that I had the ported vacuum connected to the dizzy and the manifold pulling from the PCV valve and canister in a 'T'.