scoobyady

can anyone tell me what vault signal i should b picking up for the o2 sensor on a 96 turbo 2000 through the power fc commander thanks

joz8968

iTrader: (13)

I have a 93 WRX sedan and my Commander indicates that my brand new O2 sensor is cycling between 0.04V and 0.84V.

Basically, it should continually cycle up and down, between circa 0 and 1 volt, one full cycle for about between 2-4 seconds...

Full cycle... 0 - 1 - 0 (2-4 secs period)

'Half' cylce... 0 - 1 (1-2 secs period)

mcvicar

Sorry to jump on this thread but my o2 reading on commander is a constant 5.10v. Checked the output with a multimeter conected to the white wire on a new o2 sensor and it cycles as it should. Any ideas why this should do this?
Cheers

joz8968

iTrader: (13)

Can't be right

5.1V is maximum airflow voltage as measured from the MAF . Have you looked at the wrong parameter? The parameter on Commander reads "O2-1" and you should see the value to its right actively cycling up and down, like you did with the multimeter on the Lambda's sensor ...

mcvicar

Yep thats the one fella O2-1 5.10v constant regardless of airflow settings injector settings and different map set up's.
Running like a bag of crap at the mo!!!!!

joz8968

iTrader: (13)

When you measured the Lambda using multimeter, what was it doing? Was it reading a static value or cycling properly between 0 and 1 volt?

EDIT: Sorry, you've already said that it was okay. I'm inclined to believe the multimetr TBH and perhaps the sensor for the Commander's reading is fooked . I'm confused by this one, I must say

mcvicar

no it was cycling between (from memory) 0.05v-0.82v or there abouts. The reason I changed the sensor was because it was a constant readout on the multimeter of 1.86v.

mcvicar

EDIT: Sorry, you've already said that it was okay. I'm inclined to believe the multimetr TBH and perhaps the sensor for the Commander's reading is fooked . I'm confused by this one, I must say

Yep me too

joz8968

iTrader: (13)

Is the Lambda definitely turned on, on the Commander? (TBH it must be, or otherwise the PFC would not be telling it to cycle).

Anyway to be certain, go into the 'Etc.' menu, then 'Function Select'. To the right of the parameter that reads "O2 F/B Control' is a Japanese hyroglyph for either 'ON' or 'OFF'. It need to be 'ON' which is a two character symbol: the first looks like a "7", the next looks like a 'broken' "Y", so "7Y" (lol).

If it reads similar to: "+ :/" (again lol), then it's turned off. So you need to turn it on by scrolling down to that parameter, then across to the hyroglyph, then either up or down to enable to "7Y". Then go back into the 'Sensor/SW Check' menu and check to see if it's cycling...

mcvicar

Yep thought that may be it. so tried in both on and off. Made no difference.

joz8968

iTrader: (13)

Well, as we both think, so long as your multimeter is cycling between c. 0.05 and 0.82V (pretty much exactly the same readings as for my 3 month old new Lambda), then it's defo working properly

mcvicar

Yep thats what I thought but didn't know if this reading was wrong, wether it would affect any of the other setting causing the car to run rough. If on tickover, I turn the injectors up to 105% the car will pick up and tickover very smoothly indeed. Have not driven it like this but its just a bit weird.
Heres a pic anyhow

joz8968

iTrader: (13)

Yes I can see 5.1V!... That's bloody weird

Thing is the rough running does indicate that the Lambda could be knackered... but why, then, the correct reading . Don't make any sense

I'd take it into a specialist for a 2nd opinion. Paul Blamire at Zen's pretty hot on stuff like this - I bet he'll get to the bottom of it ...

mcvicar

Just re-checked the voltage on the new lambda and now its reading a constant 13.8v

Can't have gone already surely, its only been on there two weeks.
If I disconnect the lambda the car runs as sweet as a nut and the reading on the controller drops to 0.32v.

Any thoughts!!!