Vacuum Diagram

[Dr_Snooz]

I give up. If there is a vacuum diagram in the Helm manual, I can't find it. Can anyone tell me if it has one? I'm swapping an Edelbrock for the Q-Jet and am trying to keep as much of the vacuum controlled emissions stuff as possible (CA smog check coming up). I'm looking at the diagram on the air cleaner, but it's not making much sense to me. Thanks.

[Grim 82]

Keep the ported vacuum ported, and the manifold vacuum full on. You may need to add some tees or some caps, but you can get it routed the same way that it was before. Describe the ones in question or post pics and people here will get you squared away.

[Dr_Snooz]

Much appreciated! I was able to find this vacuum diagram on autozone.com.



It's pretty much the same as what's on my air cleaner. One problem is that the four-port thermo-switch on the air cleaner does not appear on the diagram. Another is that I ran a vacuum line straight from the ported vacuum source on the carb to the vac advance on the distributor. Looking at the diagram however, I see that that circuit is much more interesting than what I've done. I'm probably over-thinking this. I do that a lot. I'll hit it fresh tomorrow and post up pics of specific issues.

Thanks!

[Lt.Del]

www.delbridge.net/vacuum.html

[Dr_Snooz]

Well, I made my best guess today. I have a couple questions below, but I was able to fire it up and it ran. Just needs some tuning and I should be good to go.

Question #1. According to the vacuum diagram above, the vacuum source for the vacuum advance comes from port N on the carb. I assume that's a ported vacuum source, but can someone confirm that? I'm questioning it because it looks like the ported vacuum switch (on the thermostat housing) is also involved in the circuit and I don't know what its role is.

Question #2 is the pic below. If it doesn't make sense, then just ignore it. I'm pretty confident it's right. Anyway, the red circles are the connections that puzzled me and the arrows are how I hooked them up. Number 1 goes to the inner sensor on the air cleaner. Number 3 I think goes to the vents inside. Number 4 is obviously the manifold vacuum source.



Thanks!