bobbarry

I've been tracking down a rough/choppy idle on my '71 for quite some time. It would start smooth, but then run rough at idle when warmed up, with the idle "hunting" by about 50-100rpms.

I've replaced plugs, rotor, cap and vacuum-advance, but it still persisted. I finally compared the vacuum-routing under the hood to what it should be:

What was under there:



After some research on the CEC system unique to '71, I realized how a previous owner had added unnecessary T's, resulting in my distributor running full vacuum advance all the time, without the CEC plunger extending to bump up the idle...

So *that's* why it ran smooth for a bit when first started, then started running rough after the timer retracted the CEC's plunger. Unbutchering the hoses solved the problem that has dogged me as long as I've owned this thing...

On the plus side, I've never checked the body-mount behind the kick-panel. Though I'm in the Northeast, this car had purportedly been garaged all its life.

From the appearance of the body-mount, I now believe it:

Greg

That's always nice to see.

CraigH

Good to see you solved the issue to the CEC setup.

i enjoyed trying to reverse engineering the CEC system many years back so I understood how it worked, then tested it all was ok, then bypassed it.

PainfullySlow

Glad you were able to figure it out. It does feel nice to finally get rid of an annoying gremlin, doesn't it?

Sabre34

Congrats on solving the problem .