Rough idle since tune-up

1990 with 4.0/around 115k miles or so.
I did a bit of a tune up the other day, including new Champion Copper plugs, a new air filter and new fuel filter. I also reset the TPS back to factory specs (usually do it once a year). I didn't touch the cap or rotor (will do that in a few days). Anyways since then, I seem to have gotten a worse idle at cold startup/gained a better idle at warm temps once running. I also noticed that even at warm idle, it *sounds* smoother but there is a bit of a "hunt", like it's missing a bit (sounds like a vaccuum leak or something). Power is great on the road and it runs better than ever, but when I start it up it sounds pretty pathetic for the first 30 seconds or so.
What could have happened? I originally thought that the computer just had to "relearn" for a bit, but it's been a week or so and it's still pretty rough at startup.

could the gap possibly be closed on a spark plug?

jneary said:

could the gap possibly be closed on a spark plug?

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Or maybe a plug wire slid in the boot and the metal part isn't seated all the way onto the plug. Could cause a weak spark which is usually more evident on a cold motor.
Moving an old set of plug wires around may have broken the insides or cracked the insulation. Do an ohm test on the plug wires.
Clean the TPS connector up well, a spot that can cause resistance and adjustment problems. I've had my adjustment change after a first and second cleaning of the connector. I now use a tiny scrub brush (for between your teeth), a premium contact spray and clean a few times a year to avoid problems. My idle used to hunt a couple of hundred RPM (warm), which turned out to be mostly the TPS circuit (connectors, splices and oxidation).

8Mud said:

Or maybe a plug wire slid in the boot and the metal part isn't seated all the way onto the plug. Could cause a weak spark which is usually more evident on a cold motor.
Moving an old set of plug wires around may have broken the insides or cracked the insulation. Do an ohm test on the plug wires.

Click to expand...

I hadn't thought of possibly damaged plug wires! Too much turkey and eggnog is my excuse!
I plan to do the cap/rotor next week, so I'll test the wires before going to the parts store...I have a sneaking suspicion that these could be the culprit.