carb air leak?, occasioally surging idle Options

[VaccaRabite]

I am having a weird issue with my carbs.

They will go along fine at 1100 RPM idle all day. Suddenly I will stop at a sign or red light and the idle will climb from 1100 to 1700 and my car will start making unsynced carb noises. Sometimes it will settle back town if I tap the gas peddle, sometimes not. Once the idle surges, it will be like that for a while when I stop, and then it will suddenly drop back down to 1100 RPM and and behave nicely.

I am guessing that I have an intermittant air leak in one of my carbs. Anything else I need to be looking at?

My theories, in order of what I think is likely:
1) air leak somewhere
2) gas leaking past the inlet valve
3) weirdness with the linkage

I have not been able to recreate the issue at home, its always when I am on the road so I don't yet know which carb is acting up. Its worse if I am driving the car hard, but will happen when I am just cruising around town some too.

Ideas?

Zach

[rhcb914]

I also vote to look at the linkage. Make sure both carbs fall back to idle at the same time and one doesn't lead the other. I've had all sorts of weird idle issues that traced back to linkage.

The other thing that I have noticed is that many of us adjust the linkage when the car is only somewhat warm or cold. The engine expands quite a bit and that can exacerbate a minor bind when cold creating a major one when hot. Well maybe not major but you get the picture.

Go beat the crap out of the car get it really hot then bring it home adjust the linkage. Make sure there is no preload on either carb.

Keep at it! It's just a machine you can beat it (IMG:style_emoticons/default/smile.gif)