Allright, guys, put on your thinking and experience caps, cause mine is just about fried. A couple weeks ago I posted a question about a problem, and it's back again. I am going to write out everything I've gone through in my process to find out whats wrong in hopes someone can think of something else!
A couple weeks ago, the wife's '02 Lancer LS started having weird idle problems. It would idle too low, low enough for the oil pressure to drop and oil light to come on. A couple times it died on her. On the way to a birthday party it started doing the same thing, and before we left to go home I turned up the idle screw just so it wouldnt starve of oil at all the stop lights. Note that it would do this at idle, regardless of whether it was in drive, park or neutral, air conditioning on or off. I checked IAC motor, ok. I removed plugs, found two were loose! Other wise plugs were ok. Checked resistance in plug wires and coil packs, per Mitsu specs, checked ok. Put everything back together, started it up, idle raced to 3000 and stayed there. Shut it off, unlpugged battery for about 15 minutes, started it up, and that must have cleared the computer because it started up and idled fine. I adjusted idle screw back down when the car was good and warm to stay around the Mitsu spec'd 700rpm +/- 100. After this it was like a brand new car. Tightening the plugs sure gave it it's ***** back. So it had been ok for the last week.
SInce then the wife has put about 100 miles on it, maybe a little less. Drove it saturday, it was ok. At end of day, sucked a quart of trans fluid out with MityVac and put in a fresh quart, since the fluid is brown. I also did this last week. Drove it sunday, on the first drive of the day, and it started to idle too low at a stoplight again. It was raining. Pretty soon, after a couple stoplights, the idle started getting so low that the car would flat out die as I slowed to a stop. Foot braked it on the way home while rolling up to lights and stop signs in neutral just to give it gas just to keep it from dying on way home! What a fun drive!!!
Sooooo, any ideas now? Here are the Cliff's Notes basics:
1. I figure since it isn't the trans since it does it in any gear including neutral, even if trans fluid is shot.
2. I checked idle air motor (IAC), took it apart, and it clicks and whirrs to life when turning ignition on, and idle dies even when the ac isn't on, so I don't think its the IAC
3. Checked all the plugs again. Tight. Cleaned them last time too. Gap was fine also. This time the very tips of the electrodes have a little white dot on them. Dont think they were there before, but also only put about 80-100 miles on the car since I cleaned them up.
4. Plugs and wires showed proper resistance when checked last week.
5. Someone mentioned battery or alternator. Battery checks at 12.4some volts. If it was alternator, car wouldn't just die at idle, would it? I would think it would die at any rpm. ??
So, I have no clue now. Through the process I described, it appeared I fixed the problem last week. It was like a new car. Now, it pops up a week later, and now the car is in the garage and wont stay running for 3 seconds after I start it. It revvs up fine with pedal, just won't stay lit on its own.
I implore anyone out there, help please!!! I appreciate ANY input you could give me!

 

PS. When I took it home to figure out what happened this sunday (yesterday) I found I had left the NEG battery cable on the terminal but not tight. So for the last 80 miles or so, have been driving around with loose battery cable. But battery shows 12+ volts when checked still. Tightened it, started car, same problem. Unplugged battery for 15 minutes to reset computer, started car, still same problem.

 

testing the IAC motor by looking at it and listening to it "whirr" is not an indication of a functioning motor.