Good evening,

My kids 92 244 w/ 96k has been having idling problem. I suspected the AMM (when I unplugged it she at least wouldn't stall) and got one from the PNP, installed it and the car ran fine for a day. Ordered another from FCPGroton, figuring the junkyard piece was bad, installed it and it still idled like crap.
When the car is cold it starts right up and idles fine. As she comes up to temp, the idle starts to lope and the car will eventually stall. If I keep the rev's up she sounds normal and seems to run fine. Changed out the plugs, checked the vacuum lines and all looked OK.
Bought a multimeter to check the AMM. I have no idea how it works so I followed the Haynes directions. With the car running I put the leads to the #2 and #3 contacts and the idle smoothed out. What's up with that? The AMM was not connected (obviously) but the car idled like it should. My codes on the OBD says I've got the car compensating for lean/rich at idle and a faulty AMM sensor signal. Like I said, I really don't know how to use the multimeter but was hoping one of you guys could tell me why the thing would smooth out my idle and if doing so either identifies a specific problem or eliminates a piece of the puzzle.
Thanks for any help.
Eric
Blue 84 front/Gold 92 rear