View Full Version : Car running rich, what could be cause?


GSBMW325is
08-10-2003, 11:56 PM
Well, pretty much what the title says, but here's some info on my particular situation:

Car is 1995 325is 5-speed OBD-1 with 87k miles. Car has Conforti intake and chip, and a UUC exhaust. These have been on the car for 1.5 years and I haven't had any problems until now. Car does not have any other engine/exhaust modifications.

Car ran really crappy a couple of weeks ago. Low idle (~400 rpms, nearly stalled), no power on acceleration (felt like 3 cylinders were running). CEL light came on with 1222 code (Lambda #1/O2 sensor reading rich/lean condition). Pulled O2 sensor, heavy amounts of carbon on it. Replaced sensor as precaution, even though I think old sensor is ok (saving it of course). Car ran ok after that, and code cleared.
Car has now developed a "hiccup" at idle. Hard to explain, sort of "bwap" noise when idling. No affect on rpms, idle's normally (~700rpms). Overall power is down, especially power below 3000rpms. It never has been great below 3000rpms, but I've noticed a distinct loss. Watched someone else drive car today, black smoke came out at 1-2 shift, has gasoline smell after running it awhile. Pulled O2 sensor, heavy carbon. Thus I think it runs rich, although I'm not getting a CEL code again..

Stuff I know is good: O2 sensor (new), sparks plugs (new NGK last week), intake system up to intake manifold (no cracks in rubber boot, etc), throttle body (cleaned). The parts of vacuum lines I can see look good.

Things that have been mentioned as possibilities as culprits: idle control valve (seems unlikely to me, but I what do I know), clogged/dead catalytic converter (maybe), vacuum line problem, compression.

I really don't know, PLEASE HELP!!!!!!!!!!! Any constructive thoughts would be great.

Many, many TIA,

Keith White

RRdawho?
08-11-2003, 03:41 AM
Sounds like your car is misfiring. Coil Packs go bad? Or perhaps the ignition wires too. Regardless if your spark plugs are new, if one or both of the two mentioned above are bad, your sparks arn't "sparking" so to speak. Check those out. My borrow a buddies coil pack or something, make sure u know it works, and go through each individual one and see if the hiccuping/misfiring stops or tones down a bit. With that kinda power loss it maybe more than just one coil pack or so.