View Full Version : Running rich...please help

11-06-2002, 09:29 PM
New engine installed with stage I cam. After all the troubles with Haynes manual firing order being wrong and replacing spark plugs because they were black and fouled from being too rich, I still have probs.

Engine will not start unless at WOT. Runs good above 1500 RPM's but seems rich. Below 1500 it coughs, spits, shakes and dies in a hurry.


KOEO 173 = O2 sensor indicates rich condition, right side

KOER 411 = Unable to control RPM during low RPM self-test
KOER ??? = I can't remember the number but it said rich on left side

I hade to hold the throttle open a little to stay at about 1500 RPM's just to perform the KOER test. It never completes the test and dies (probably the 411 code).

Could I have bad O2 sensors? This thing is running RICH. No visible smoke but it's an eye burner!

Please help!!! Thank you.

11-07-2002, 12:02 AM
I would have to think you have a little more going on than o2 sensors, not that they could not contribute to richness...they can...But your idle is aparent that you have other things going on. You may wanna check your firing order again, and your wire to plug placement...Keep it simple for now...SInce you are not getting a sensor code I think the car is kinda confused why it can't keep idle at low RPM's...THat is a start...I would be paging doctor FRED if it were mine...best place to do that is TBSCEC.com* in the performance section there...He comes here as well I think....

11-07-2002, 03:01 AM
i would also check the temperature sending units along with the wiring. i worked on a datsun 280z once that did the exact same thing. the temp sending unit connection was corroded so the computer thought the car was always cold. that one took me a while to figure out in my early hot rodder days...