[krahm]

This car has been running poorly ever since I bought it. It's an 87 "S." Vacuum level is low I think, at 14 in Hg, but I've done the seals, lines, gasket, etc. As I understand it, that should make the car run rich. But the car runs kind of hot, the plugs have barely any ash on them, so I'm thinking it's running lean for some reason (the plug on the AFM adjustment screw has been pulled, so someone has been ... er ... screwing with it before me). It runs like crap with the 02 sensor connected (which I replaced last year), but better with it disconnected.

When I attached the digital voltmeter to the prong on the 02 sensor lead, unplugged, and I set the meter to the 2000 mv scale, it read 3. I was thinking the mixture was WAY too lean, so I started richening the mixture. I got it up to around 140 mv, but that's as far as I can richen it (screw stops turning). Shouldn't I be getting a reading of 500 to 600 for a correct mixture on the 2000 mv scale? Or am I confused? I've had the AFM off the car to test it and re-track it, and it looked like it was okay. Am I doing this all wrong or what?!