Fuel tunning question. I'm puzzled.

[BlueShark]

My car is little bit weird. Here is the situation.

3rd gear pull from about 3000 up to 6500rpm, 16psi, pump gas.
EGT hits around 820-840*C <- it doesn't seem to be leaning out.
New O2 (which was put in yesterday) reads about 770-800mV at the end of the run.
O2 reads up to 1100mV during a warm up <-sensor seems to be working.

I know O2 sensors are not accurate enough to go by but it really puzzles me. When I richen it up, I get black smoke cloud behind me with O2 reading of about 820-850mV.

I guess you could say this is a primitive question but would you guys say that I'm running rich "if I get a black smoke" out the back even though O2 reads 820-850mV?

Give me your opinions on it please. Thank you.

 

[turbolover2]

Black smoke means the car is very rich. I'd carefully lean it out a little at a time, and watch the EGT closely. I wouldn't go by the O2 readings too much, the sensor doesn't seem too accurate (with black smoke you should be getting a 900+mV reading).

If you can spare $150, invest in a PocketLOGGER. It will help you a lot.

 

[BlueShark]

Thank you for your advise. I agree with you. I am sort of double checking it cuz some people's been telling me that I "should" be puffing out black smoke which I disagree with.

Oh, I get my datalog via Haltech.

 

[BlueShark]

anybody else?