: Running Rich?????



CYFAIRCADDY07
07-29-05, 02:15 PM
I performed the Diagnostic thing on the car several times and continue to come up with the Rich code.
How shoul di go about getting rid of this???

mcowden
07-29-05, 02:39 PM
First things first: Why did you do the diagnostics? What symptoms is it showing?

If it's running rich, there could be a number of reasons. MAP or MAF sensors, TPS, leaking FPR, leaking injector, bad O2 sensor(s), etc.

Exactly what "diagnostics" did you run and exactly what were the results? Codes? Which codes? Were they Current or History? Was it running when you ran the diagnostics?

first sts
07-30-05, 09:35 AM
Question for mcowden: If the O2 sensors never read higher then 5 on a scale 0f 0-255 and they have been replaced [old ones read the same numbers] is there something else controlling them ??????

mcowden
07-30-05, 02:07 PM
Someone else may know more about this than I do, but I don't know what the scale of 0-255 means. The output from an oxygen sensor varies between 0 and about 1 volt. The higher the voltage, the less oxygen is in the exhaust. When the computer reads maybe 0.8 to 0.9 volts from the sensor, it reduces the injector open time (pulse width) to the group of cylinders indicated by that sensor. If the O2 sensor voltage is 0.1 to 0.2, it raises the injector open time. The voltage from the sensors varies constantly. The up and down action of the voltage is called switching. If the computer senses that the variations in voltage are not happening frequently enough given the variations in injector pulse widths, it gives you a code to indicate that there is insufficient switching occurring on the sensor in question. The sensor may be dirty or may have just corroded internally to a point where it no longer effectively senses the amount of oxygen in the exhaust.

If you're not getting any codes for oxygen sensor problems, that may not be the issue. Maybe a leaking fuel pressure regulator or fuel injector is more to blame for the problem. Have you investigated anything along those lines yet? Can you elaborate any further on exactly what you are reading from the oxygen sensors?

first sts
07-30-05, 04:24 PM
Sorry,,,the numbers refer to the cross counts 0-255 In my Buick GN the cross counts stay around 128 when reading is low 90-110 it means the car is rich and the computer is taking away fuel, higher is lean computer is adding fuel....My STS voltage seems to be allright but I will have to watch them the next time I drive it to see what they are reading, no codes just a very black sooty exchaust area around the back of car gas milare 17.5 around town, 22.5 on a trip with A/C on. Have done on board computer testing of injectors and found nothing have not checked regulator,,,,

mcowden
07-30-05, 04:34 PM
Sorry,,,the numbers refer to the cross counts 0-255 In my Buick GN the cross counts stay around 128 when reading is low 90-110 it means the car is rich and the computer is taking away fuel, higher is lean computer is adding fuel....My STS voltage seems to be allright but I will have to watch them the next time I drive it to see what they are reading, no codes just a very black sooty exchaust area around the back of car gas milare 17.5 around town, 22.5 on a trip with A/C on. Have done on board computer testing of injectors and found nothing have not checked regulator,,,,

I don't know how you can check injectors via the on board computer, but either way, that will not tell you if they're leaking or not. They can leak if there are deposits around the nozzle so the pintle doesn't seal the hole completely, or if the spring is broken for some reason.

From the sounds of what you're describing, it's not running rich at all. How much oil does it burn? You might just need to do some wide open throttle work to help blow the carbon out of the combusion chambers and exercise the rings a bit. The mileage is about normal. Look at a graph of the O2 sensor readings as you're driving and let us know what you see. You might also consider switching gas stations. What kind of fuel do you put in it?

CYFAIRCADDY07
07-31-05, 02:09 PM
P080 code while off was the code it is showing and it is current.

mcowden
08-01-05, 03:28 PM
P080 code while off was the code it is showing and it is current.

Have you checked for a leaking FPR or injector yet? What symptoms do you have? Hard starting? Bad mileage? Stinky exhaust?

mcowden
08-02-05, 04:51 PM
Here's a good quote about oxygen sensor voltage from Larry Carley:

"An oxygen sensor will typically generate up to about 0.9 volts when the fuel mixture is rich and there is little unburned oxygen in the exhaust. When the mixture is lean, the sensorís output voltage will drop down to about 0.1 volts. When the air/fuel mixture is balanced or at the equilibrium point of about 14.7 to 1, the sensor will read around 0.45 volts."

CYFAIRCADDY07
08-02-05, 09:24 PM
Thanks allot.
It seems to have just disapeared, :disappoin .. no code no symptoms.

budkidd@fuse.net
09-20-07, 11:35 PM
my car did it and it was half the coilpack wasnt working

budkidd@fuse.net
09-20-07, 11:36 PM
check your coil pack

clarkz71
09-21-07, 12:50 PM
The last time that guy posted on this forum was............2 years ago. He's probably fixed it by
now, if he still has the car,.


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