1982

1982 22R PU with stock Aisian 35160 2-bbl carburetor. On the secondary bore choke rod, on the end facing to the rear, there is a tiny bias spring to keep the choke plate closed. On the flange where the spring is mounted, there is a hole with nothing in it, on my setup. Am I missing an actuator rod? I don't see how the plate will ever open as it's always biased closed.
Any ideas?
The primary bore choke plate has an arm going down to the base of the carb linkage to actuate it.

1982

No responses here so phoned a carb distributor. He claims I'm not missing any actuator rods and the secondary plate will open on its own when the secondary throttle plate kicks in. I suppose it sounds reasonable but I can't get the secondary throttle plate to open while I'm under the hood and the engine isn't under load?

JonnyBoy

My '83's carb wasn't rebuildable, so I never really looked at it that close...but is the Aisin a vacuum secondary or mechanical? If it's mechanical, you could see the secondary throttle plate open even if the engine is off, if it's vacuum, it won't. Only thing I can think of is that it's vacuum operated and the engine doesn't need the secondary when it isn't under load, so it won't open. If it's a mechanical secondary, I'm not sure what to tell you unless you're mistaking that choke plate up top for the throttle plate.
Hope that helps, and I apologize if it doesn't.

1982

All is well. I let the motor run and get good a warm today (the truck has been sitting for 10 years) and once the secondary throttle plate was allowed to engage, the "upper secondary plate" did in fact open when I gave it full throttle. The force of the high velocity air being sucked in is what drives it. It appears this upper plate isn't really a "choke" per se but what it does is raise the power piston which allows more fuel to be metered into the secondary throat on acceleration.