The Stovebolt Site Forums The Shop Area Engine Shop edelbrock 1406 question

I have a 327 with a mild cam, edl. intake and 1406. Over the past couple weeks i have been noticing the idle dropping. I have checked everything i could think of- vac leaks, timing, valve lash, cylinder compression, the list goes on; and it all seems to be in good shape minus a small exhaust leak. However, the one thing i am unfamiliar withis the carb. I know quadrajets, holleys, even a little on a four jet. A friend of mine with a bit more knowlege than i stopped by and wanted to see what he could do to figure out the problem. within all of 2 minutes of the truck being fired up he had a nice idle, a little high but he said it needed to be retuned to drop it. He showed me what he did; he moved the fast idle cam and screw into what he said was the proper postion, and told me to file the cam a little so that the screw could return to rest there when i get off the gas. He showed me that when the excelerator is pushe, the screw goes behind the cam and does not slide back to where it was, but instead it sticks behind the cam. I dont know enough about this carb (or anythin really) to modify it like that, so im asking for input, like has any one heard of doing this? I have tried adjusting the idle speed screw, and idle mixture screws, but without much luck. I have not changed anything on this carb from when i took it out of the box, other than the idle mixture screws and the idle speed screw.

I would not mess with the carb yet. First of all, you noticed the idle dropping? Meaning what exactly? You mean it consistently idles lower than before? or goes up and down? or you don't like the low idle? Second, there is an idle adjustment screw to open or close throttle blades. That's how you set idle together with trans either in neutral (manual trans) or in D (Auto). The carb you have is a Carter Aluminum Four Barrel (AFB) with an Edelbrock name. It is a good carb and very easy to rebuild. Your friend is wrong about the need to file anything. If he says it "sticks" behind the cam, doesn't that make it idle too high? but you say it's "dropping". Adjust the Idle to the specified RPM's (600-700) and be done. Idles can go down over time because of dirty air filter. Don't understand "not having much luck" adjusting idle, it's just like pushing on the pedal. The idle HAS TO GO UP! I don't know the age and condition of ignition or carburetor components but I would: Refresh distributor components, new plugs, wires, air filter, time it, then set idle. In other words, a tune up. Fix exhaust leak. Super bitchin motor.

Could be some trash has made its way into the carb and blocking the low speed (idle) circuits.

Those are nice carbs and don't usually require a lot of tweaking once set up. So may be time to clean it.

Roger, Roy.

The choke should open enough so the fast idle screw gets off the fast idle cam & the regular idle speed screw takes over.