Rough idle after tune up

[Rascal]

Car was getting a little harder to start and was losing power when cold, so I replaced points, condenser, rotor, dist. cap, wires, plugs. Started right up but idle was very rough, engine chugging and shaking. I checked the plug wires, points gap, looked fine.
I adjusted the advance by ear, which helped a little. So one-by-one I put back the old wires, condenser, rotor, plugs, no change.
The old plugs looked fine, nice tan color. It drives somewhat ok, but rough at low speeds. Obviously something I did is the problem, but I'm not sure what it is.

Car is '76 1800, converted to single points. It idled fine (when warmed up) before I started. Points are set to .017"

What should I check next?

[124JOE]

any air leaks around the base of the carb
use carb cleaner spray to test
also around the intake

or vacume lines

[majicwrench]

Spraying carb cleaner around is an excellent way to start a fire.

As you mentioned, it is likely something you did. Double check firing order. Pull and inspect new plugs for cracks or gap issues.
Keith

[So Cal Mark]

sounds like you mixed up the firing order

[ventura ace]

Yes, check the routing of the wires. Also check the new cap as compared to the old one. There are 2 very similar caps, that are identical on the outside, but different on the inside. One has a much deeper distance to the contacts, which could make for a big air gap between the contacts and the rotor.

Alvon

[Rascal]

I double-checked the firing order and plug wires, put back the old rotor and cap, same problem.
I did notice a marked increase in noise from the valve train, a distinct "clattering" noise that wasn't there before.
The oil level is good and there seems to be plenty of oil on the valves as seen from the filler cap.

[So Cal Mark]

I'd take all of the spark plugs out and determine which cylinder had something fall into it. You'll probably have to replace the broken spark plug

[Rascal]

So pull the plugs one-by-one, start it and the noise may go away for one?
All the plugs look ok.

[majicwrench]

With our fiat plugs sitting down in a hole, anything, rocks, bolts, gravel, UFO's whatever, ends up in the cylinder when you remove the plug. Mark suspects, and it is likely, if it is now noisy, that something has fallen in. Pull all the plugs, all at once, and inspect. BEFORE YOU PULL PLUGS YOU MAY WANT TO BLOW DEBRIS FROM PLUG AREA. You will possibly find one that shows some damage. That is probably the cylinder that has something in it. Take a small light and peek down the plug hole, and again, see if you can see signs of damage--dents, shiny spots on top of piston. If you find a cylinder that has something in it, now you need to get "something" out. It may blow out if engine cranked with plugs out. You may want to try a flexable magnet. A vacuum cleaner as you crank engine. "Something" may have stuck itself to the top of the piston, and that will take more work. First things first, pull plugs, and take a peek.

[Rascal]

Thanks for the advice, majicwrench. I'll try to take a peek down inside.