O2 sensor

[Eduardo Castrejón Elbjorn]

1984 auto

I recently replace the o2 sensor with a bosh replacement for this car.
I bought the car with this sensor disconnected and when I took out the old sensor was completely yunk.

The sensor is already in place, but I don´t have the conector in the firewall, but I will weld.
I don´t already did it because I want to use it to calibrate the maf (without succes), then I will do it soon.

If my memory is correct I red in this forum that, when the engine is in normal driving temperatures and you disconnect the 02 sensor you can feel, note or ear a change in the engine. I really don´t feel any diference. But I supose that is not very notorious, but obviously the 02 sensor is the one of the most important parts in this kind of fuel injection.

My question

After this sensor is completelly connected, Can I tried if works properly in the computer ?, I want to know if my computer have the signal from the o2 sensor, Can I test this ?
let me know
regards

[todwic]

yes, there is a test, I get it for you tonight. Firstly, do you have the CA (heated lambda) or the ROW (unheated) sensor? Heated you can check in 30 sec. ROW (rest of the world) you need to let the exhaust theat heat the lambda before you'll get correct values. (approx 3 min) Visit FRWilk's site, it's very informative about our early cars. early 944

[Eduardo Castrejón Elbjorn]

Yes, I have the 1 wire unheated bosh O2 sensor,
thanks, I will apreciate a lot

[Roastin944]

So the 3 wire ones with 2 white wires and one black wire are unheated? My air fuel gauge takes a while to read right, reads once the engine is warm, and goes from the lowest bar to almost getting rich and goes back and forth, like that example above but it goes lower, is that wrong? Thanks

John

[Wolf1]

Use the following chart to help guide your way to maximum power!
METER READING FULL THROTTLE AIR/FUEL RATIO
.000 17.0:1
.100 17.0:1
.200 16.0:1
.300 15.5:1
.400 15.0:1
.500 14.7.0:1
.600 Dangerously Lean 14.6:1
.700 Getting lean 14.5:1
.800 Max power(Lean) normally aspirated 14.2:1
.875 Max Power normally aspirated 13.5:1
.900 Max Power (Rich) (NOS,blower,Turbo) 13.2:1
1.000 Very Rich 12.5:1

Actually many vehicles will cycle the full range of the sensor from below 100mv to over 900mv when at cruise rpm. The critical reading is at wide open throttle under full boost this is where you want to see a steady 900mv, some tuners will lean things out a little bit and gain a few extra hp, but 900mv provides a small margin of safety. Most current OEM systems run 900mv at full throttle. The air/fuel ratio's compared to the sensor voltages on this chart may be off a little, Vortech claims 900mv translates into 11.5:1 GM scanner readings claim 900mv equals 12.5:1 . The world may never know!!!!!!!

[todwic]

I see I left Ed in capable hands.

[Eduardo Castrejón Elbjorn]

thanks for all your answers

Yes, I understood the air fuel ratios.

I don´t have an air fuel ratio gauge, I had one but I sold my race car with the gauge.

I try to set airfuel ratio with my rebuilded maf with the 02 sensor like says in the early944 page with a multimeter but if at Idle the air fuel ration all the time jump from lean to rich then how I can detrmine the correct position ?

all this is very useful and good to know but my question is:

Can I tried if works properly in the computer ?, I want to know if my computer have the signal from the o2 sensor, Can I test this ?

[awilson40]

It will jump from lean to rich on a multimeter. From .3 to .7 v is very sensitive. Try adjusting rich until steady at .7 to .8 v, then adjust lean until it starts fluctuating again.
Your other question. You have to check the voltage at the computer pin 24. However...if you check the voltage at the connector in the engine compartment with the O2 sensor disconnected, you should read .45 volts on the female pin of the connector that goes to the computer. If you read this, then the connection to the computer is good.

[Eduardo Castrejón Elbjorn]

thanks for your answer awilson

I will check this weekend

About the 02 sensor connections

female pins

I don´t understand this

my 02 sensors connects to 1 wire only, green wire near to the firewall, maybe you have more wires heated or ?

[awilson40]

Yes, you are right...only 1 wire for yours. Mine has 3 .
2 are for the heater

[Eduardo Castrejón Elbjorn]

ok, then to check the 02 sensor will be the same reading ?