Here’* a little test. Well, not really a test, I just want to see if anyone else thinks the same way I did…what kind of diagnosis you might come up with.

Car: 93 SSE (n/a), 195k miles

Symptoms: Car “stumbles” at idle (i.e. does not idle smoothly) – idles ok, stumbles, idles ok, stumbles (not cyclic, however, no “rhythm” to it). Seems to run fine otherwise (no noticeable hesitations, surging, etc. while at speed or under acceleration).

Recent maintenance (within last couple months): New alternator, new radiator, replaced power steering pump, new tires. (Some or all of these may not be applicable to problem, just giving you information that was available to me).

What do you think the problem was (it’* fixed now)? Ask questions if you need more information.

EGR Valve?? My Sebring was just like that, idle was crappy and all over, but no loss in power.

EGR isn't functional at idle, but if there'* a leak in PART of it, it could affect idle by letting in un-metered air.

I'm betting the dirty TB/IAC was the issue, or a vacuum leak.

Haven't we had people of this cars vintage having these problems caused by exhaust manifolds leaks also? they are sucking in outside air and causing the O2 sensor to adjust on false data.

I'd look at plugs and wires.. check battery connections and look at the O2 for wire # 4 and 6 possibly touching it.

Thanks for playing. It'* about 2:30 here. I'll give you until 3 pm my time for any more thougths. Good answers so far, but I won't tell you if any of them are right...yet.

Interesting that nobody mentioned the fuel system. No matter, 'cause that wasn't it. I had all kinds of things running through my mind and rather than shoot blindly I had it scoped. Turns out the coils were working overtime trying to keep the fire lit because my sparkplugs have been in there since 1927. Everything else was fine. I'm such a DOLT. I didn't think the plugs were that old, but the truth is they've been in there for a very long time. To add insult to injury, I'd actually looked at one of them within the last month. Gap was a little big at .063, but otherwise looked fine. They were Bosch platinums, however, with the electrode that is flush with the insulator. Closer inspection reveals that the electrode has burned down into the insulator.

So, bottom line - a new set of plugs and she'* purring like a kitten. And because I'm such a dumba$$, I've already scheduled myself for a flogging.

Thanks for humoring me by taking the quiz. While Boosty was the only one who mentioned plugs, I'm certain if the rest of you had more information (which I purposely held back) you'd have nailed it right off. I didn't. I was ready to swap the engine.

The reason nobody nailed is because most of us replace our plugs fairly often, particularly at the onset of ignition-miss problems.

Course Boosty was right , he had 10 guesses ha ha

EXACTLY! That'* why I left that particular bit of information out of the equation. I can't believe I left those plugs in there for so long! Although you guys probably wouldn't have believed anyone was as big a conehead as I am and hadn't changed my spark plugs in the last decade (aren't they supposed to last for-ev-er?). I had myself sufficiently flogged, however, and won't be changing plugs at 30 year intervals anymore.

Boosty cheated and shotgunned the answer: "I'd check the wiring, gas, plugs, rotate the tires, recline the seat, sniff the exhaust...
LOL!