gruveb

OK. I just slapped on my Holley 4011 series 650 carb in favor of the Edelbrock 600 cfm I was running.

Low end is much, much better. The carb is used, and needs some work....but I'm an idiot about these things.

The secondaries do NOT open. I can open them by hand, but they don't open by themselves.

At first it felt like they were sticking closed so I cleaned everything up, and now they move freely by hand.

However, when you open them by hand, they close up, but the idle still stays way high....even though that the secondaries are closed and the primaries are where they should be for idle.

The idle will stay up like that for about 2 or 3 minutes (literally) before settling back down.

So, what could cause the secondaries to stay closed? (Nothing is in the way physically)

What would cause the engine to continue to maintain a higher RPM (2,300 rpm) after the secondaries have been closed?

Vader

4011 - Vacuum secondary? (Similar to 4160) Make sure the little "nipple" between the secondary diaphragm housing and secondary metering plate is in place and sealed. These are a PITA.

Of course, the secondary air valve diphragm, retrun spring, and linkage must be intact.

gruveb

I'll fumble around a little bit and see what I can break!

I'll post some potos so that someone can help me identify some of the parts.

I'm as inexperienced as they come with carbs!

a73camaro

There is a Holley tuning book out there that has good examples of how the carb goes together.

Two ways to test a vacuum secondary.

First, unbolt the canister and depress the throttle rod until it bottoms out. Now cover the hole that get it signal from the venturies. If the diaphragm is sealed off good, the throttle rod will stay put. If it releases, the diaphragm is misaligned or torn.

Second, with a complete carb of the engine, fully open the primary throttle and blow compressed air thru the passenger-side primary venturi. This will cause a "vacuum" in the venturi an open the secondary throttle, if all is good. You may have to "hunt around with your air nozzle to hit the venturi "right".

gruveb

What's the name of that book?

I like pictures!