Carter/Eddie AFB question

Bewy said
[1] The first thing to check is that the passages in the AFB base are covered by the gasket/manifold flange. If not covered, you will have a large air leak which would explain your some/all symptoms.
[2] Engine idling, remove the PCV & make sure it is pulled in. If not 'in' or vibrating it is adding varying amounts of air & playing havoc with idle air metering.
[3] The cheap [ & simple ] fix for [2]: get a 3/8" diam bolt & cut off a 3/8" length of it. Drill a 1/8" hole through it; push into the PCV hose. You now have a functional PCV.
[4] The ProCrap 850 probably had adjustable by pass air, & this carb may need it too.
[5] Not time for drilling holes....yet.
[6] Single plane, & a Victor, will provide less vacuum & exacerbate the problem.
[7] What are the cam specs & timing at idle? See below.

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Wow, 50 deg BTDC at idle can be optimal! I have sort of seen that several times. The Holley 1920 on my 1969 slant-six was quirky, always idling rough and wanting to die. It was happier with >20 deg advance at idle. If I tried to set to the book ~5 deg, then gave a little throttle the engine would race up in rpm which, giving more advance which it seemed to like. Shifting to "D" would bog it down, rpm dropping low where it lost advance and would often die trying to leave a stop light (bad for wifey). I had tried many things, rebuilding the carb myself, 2 store rebuilt ones, valve job (per mechanic). Finally after a whole new long block still wouldn't idle well, I tried a 4th carb and it idled like a kitten purring and no more bog leaving a stop sign. I suspect it was running lean with all the other carbs, both from wanting so much advance and because unscrewing the idle mixture didn't help much. So the carb can be the culprit, and hard to know what is going on inside, especially in those days without an O2 sensor.

Dealing with that last week with my 1964 slant w/ BBS carburetor. It wanted 35 deg advance to idle without dying, and still rough. Strangely, long ago when I bought the car, it idled so smooth you could hardly tell the engine was running. Since then I changed to an electric fuel pump and GM 8-pin HEI ignition. Installed an O2 sensor and meter, but it just shows full rich all the time. I'll approach it methodically. Bought a piston-stop to verify TDC mark, check fuel level in carb, rebuild carb, bought rebuilt Mopar e-distributor to replace new one (Chinese?), will drain and refresh the gas. I think the engine is fine since it ran so well before and still runs smooth when idling >1500 rpm.

The public thinks old engine controls were simpler to diagnose and repair. Not true. After a re-ring of my 1996 Plymouth 2.4L (fix endemic head gasket oil leak), it fired right up. As long as you get the camshaft marks aligned, there are no other adjustments. Spark is perfect from the crank-triggering and all settings in the engine controller software. As long as your engine is stock and good compression, it "should work". Easy to verify via O2 sensor plots via OBDII adapter. Not so with an after-market controller, since back to fussing with spark timing and O/F adjustments, though easier fussing via PC settings than mechanical adjustments in a carburetor and distributor, and auto-tuning software simplifies it.