hmm...fuel injectors = rough idle??

[Jareds 89 LX-i]

Ok lately my car has developed a slight roughness, or maybe more of a "miss", only at idle. Everything above that is perfectly normal, and she's got just as much power as she's always had. I've been brainstorming a few things, but I'm not sure. At first I thought maybe one (or both) of the intake manifold/throttle chamber gaskets were leaking, since that's what happened on my sisters Maxima and it caused it to be rough only at idle. But all those gaskets were replaced when I did the head gasket back in October, and I've only put 20k miles on since then, so it shouldn't be that. I also thought maybe vacuum hoses, which it still could be, but I looked over them all and all seemed to fit tightly and none were dry or brittle. Also on a vacuum test, I was getting 21 in-Hg of vacuum, and it didn't flucuate at all, so I would think that would show a vacuum leak if there was one, maybe (?). I haven't done a full tune up lately, but it hasn't been that long. I replaced the wires just a couple months ago with NGK's. Spark plugs might be about due though, so maybe I'll just do a tune up anyways.

Now I'm thinking either fuel injectors or distributor. I know the distributor has never been replaced, and only 2 fuel injectors were replaced (@ about 180-190k), the other 2 are still original with 294k. I know when a fuel injector went out on my sisters Maxima it didn't give any warning (roughness or anything), it just up and quit (then it got rough! lol). Would dying injectors cause a rough idle? I'm sure a dying distributor would, but I'm not sure how to check that (if anybody knows, please tell). If I remember correctly, I can check the resistance of the injectors with an OHM meter, right?

Any other suggestions? This isn't a "rough as a pig" type thing, just a little roughness that's enough to be annoying. Sorry if this sounds kinda jibberish, just typing as I'm thinking here, lol

Thanks!

[Jareds 89 LX-i]

damn it....wrong section. Supposed to be in technical...sorry!

*smacks himself on the head*

[POS carb]

if it's sealed up ok then I'd check the ignition (plugs, wires, coil)

[1988starter]

Get a new cap rotor pcv valve and clean the throttle body for me that was about 20 bucks and it did wonders.

[Jareds 89 LX-i]

Ok I'll try the tune up first. If that doesn't cure it I'll tinker around with some other stuff.

Thanks!