Worked on steering column

[theholycow]

My Buick's tilt steering column was wobbly so I took it apart to tighten the screws that had backed out.

I put it back together and started the car, and now I think it's running worse. First it was hard to start and backfired through the intake badly, making a ton of smoke. Then it had a louder BLATBLATBLATBLAT sound from the intake than normal. After a few minutes I don't know if I got used to it or it warmed up and went away. It's idling even higher than usual. At first vacuum was low but it came up after a few minutes.

I test-drove it and, apart from the high idle, it seemed pretty consistent with what I expect.

Even after I removed the vacuum advance it idled higher than expected.

It could be a coincidence. It might just have randomly hard-started and I gave it too much gas, causing the backfire (seems unlikely). On Thursday I broke some spark plug wires and replaced them with some old ones. The weather has been dry and sunny since then. It's been raining since mid-morning today. I could have some misfiring from those plug wires (or maybe I had it with the other wires and it's gone from the replacements). However, disconnecting them at idle (including the ones that survived Thursday), they all produce the same result - barely perceptible difference.

Any idea what's going on? I'd hate to drive it to work tomorrow and find out that I'm destroying the engine due to a broken wire in the steering column.

The ignition switch isn't in the steering column. The key cylinder is but there's a mechanical linkage to the ignition switch under the dash. I don't think a wire from the ignition switch is messed up, and I don't think it's possible to put the linkage together wrong so the ignition switch is operated incorrectly (nor do I know how that would cause these symptoms).