I think my vacuum advance is not working. What's happening is kind of 2 fold when I come to a light and I am idling the idle rpm will drop as much as 200 rpm after about a minute. Then after driving at highway speeds for a while I find on the off ramp the idle is down to about where it is at the light.

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2006 Jeep Commander
2013 Chrysler 200

1964 Valiant 4 Door
1965 Plymouth Barracuda
1967 Chevy Camaro

Sounds like a vacuum leak to me.

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Joshua

Pull the vacuum line from the advance pod off the carb side, plug it up on the carb, start the car up, and then go suck on the vacuum tube. See if you hear any audible change in the motor. If you don't get resistance when sucking either your advance pod diaphragm is blown, or the line running to it has a crack or hole in it.

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1968 Plymouth Barracuda [Daily Driver]
1972 Dodge Dart Swinger [Lent out as Daily Driver to a friend]
2010 Challenger R/T 6 Speed

Not to hijack, but related question...
Can the advance pod fail but not completely? Or does it just blow out. When I use a timing light and disconnect vacuum, the timing changes so can I assume it's ok?

Generally what happens when a vacuum pod fails is the rubber cracks and or the tubing connecting pod to carburetor cracks. This can cause a very small leak or total inability to hold any vacuum.

An easy way to test a diaphragm is to disconnect vacuum tube at carburetor, place that end of tube in one’s mouth and suck on it holding a vacuum with tongue over tube’s end. If diaphragm won’t hold a vacuum it has failed, also one can observe vacuum advance this way with timing light when engine is at idle.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

All right so I am getting vacuum on the carburetor to distributor port and the distributor does seem to be holding a vacuum.

I think I am going to try and rebuild the carb again make sure ALL the check balls are there. The carb seems to be leaking a bit also so I am thinking the gaskets aren't sealing.

Whats weird is around town it works great its only when I have traveled a distance.

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2006 Jeep Commander
2013 Chrysler 200

1964 Valiant 4 Door
1965 Plymouth Barracuda
1967 Chevy Camaro

I still think you have a vacuum leak. That you're having problems between when the car is good and hot as opposed to warm or cold reinforces this. I have a German slant 4 car and I had idle problems and part throttle misfires until I fixed my vacuum leak. There are 3 gaskets, an air cleaner support, and insulator between the carburetor and manifold of my little car. So there were more than the usual number of leakage paths.

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Joshua