Good morning all
I am new to the Holley 1920, and I have one that is giving me grief. Here's a short description of what's happening:
Idles fine, and gives good power at full throttle, but off Idle has a horrible misfire. If I manually apply the choke, it smooths right up. I am assuming that I have a problem in my idle circuit. Idle air bleed is clean, idle mixture screw is clean and not damaged, and the carb seems to be clean overall (previous owner said it is a new remanned carb).
I noticed during cleaning that the metering tube in the idle well is loose (will move up and down in the well by flipping the metering block upside down). Normally it will hang down so that the tip of it can be seen behind the main jet, but if you apply air pressure to the main jet the rod will move up in the well and seat against the expansion plug at the top of the metering block. I saw somewhere in an old thread where slantsixdan said that that rod is not supposed to move. This seems to me to be the source of my lean off idle condition.
I am wondering if anyone here has any experience remedying that issue, or if it means I should start trying to source a new metering block. I know the expansion plug at the top can be removed, but I don't know if that metering rod is supposed to be a pressed fit in the metering block or not.
This forum has been a godsend up until this point, lots of good knowledge out there. Any help would be greatly appreciated.

Just a thought. With the engine running spray some water on the intake manifold around the head and the base of the intake where it meets the exhaust manifold and see if the idle changes. The part where you state that it idles rough until you apply the choke just makes me think about the kinda common issues with intake manifold air leaks.

Personally I am not the 1920 whisperer that you need and my memory is fuzzy on them anyways.

Please include some other info on the car. year, general state of tune, history if available....

Ive looked pretty thoroughly for vacuum leaks, I've been shooting carb cleaner around the carb and intake with the rig running without any noticeable change. I have also checked the PCV valve, vacuum advance canister, choke diaphragm, etc. to make sure I'm not loosing any vacuum there. I will focus more attention at the manifold to head seal just in case I brushed past something without noticing, I have spent most of my time looking at the carb.

The car is new to me. The story goes that it had been sitting for 25 years, and the the previous owner picked it up and put some work into it to get it running. Its had a lot of new parts put on it (water pump, brake master cylinder, hard lines, belts, etc) but the only thing that would affect this issue would be the re-manufactured carburetor that he installed. Ive only seen the rig run for about 30 seconds to get it on a trailer, so I have no idea if it ran this poorly when he had it. Sounds like he hasn't put many miles on it at all since doing the work to it. I cracked some timing into it (8-10 BTCD) and it helped pick the idle up some, but other than that I have not dug too far into it other than pulling and cleaning the carb. the carb has a sticker saying it was remanned in 2025. So far the only thing that is out of the ordinary to me about the carburetor is the aforementioned metering tube in the idle well.

That's not good, it's bad. "Remanufactured" carburetors are junk, just about categorically.
Big fail. This is not okeh, and also not really fixable except by replacing the metering block. It is probably not the only problem with this "reman" carb.

More info, please: year, model, engine, transmission? If '70 or later: California, or 49-state/Canada car?

Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here, but it doesn't sound like you've got a good candidate for repair on your hands at the moment.

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Pleasure to meet you Dan. Its a 1971 Dart 2 door hard top, 225 with a 904 automatic. It was sold new in California, and spent all but the last few years there.

I have disconnected and capped the vacuum line going to the air cleaner diaphragm, and I tried running it around today with the vacuum advance disconnected and capped (Just to see if timing would make a difference). Still runs poorly. I have been fiddling with the mixture and idle, and it seems to me like there's a fuel restriction somewhere in the idle circuit. It feels like it will move enough fuel to idle well, but the second you crack the throttle it starts to pop and miss. I've put 20 or 30 miles on it in the last few days trying to diagnose it, and it will idle strong (No throttle input needed to move from a stop). I might pull that expansion plug from the top of the metering block and see how bad the situation is in that idle well. I am afraid that I will need to source a new carb to rob parts out of though. It doesnt look like it has EGR, my only vacuum lines from the carb are for vacuum advance, PCV, and the air cleaner diaphragm

Hiya.
Okeh. So that car has the '70 California + '71 50-state/Canada evaporative emission control system described here, which you'll want to make sure is in good condition and hooked up correctly. It also has a vacuum advance disabling system tied into vehicle speed, which you will want to bypass (hose directly from carburetor to distributor).
Once verified no leak, put that back together.
You will need to source a good carburetor. Trying to rectify this "reman" unit is not a good way forward.
First year for that was '73

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.