a/f gauge shows voltage when not running?

[90Acclaim]

Is this normal?

My a/f gauge shows voltage, like 3 or 4 bars when the o2 sensor is totally unplugged and the car is running...

... it also very slowly goes up the voltage scale to about 5 bars when just the ign is turned on.

Is this normal.... it doesn't sound normal? All the wires are soldered well... but I will sadly admit, I have it with a shared ground with some other gauges.

And yes, the car runs richer then it should.

- Jim

[detobias]

when you unplug the O2 sensor (engine not running), try grounding the signal wire (the one running to the computer) and then see what the AF gauge reads

if it aint 'no bars' then you got a wiring problem

[Omnibus]

Quote:

Originally Posted by 90Acclaim I have it with a shared ground with some other gauges.

It is my understanding that "that is an absolute NO-NO"!
It's an easy fix, and won't hurt anything to create its own proper ground.
my two cents - Andy

[90Acclaim]

Should I be showing voltage in the first place, when the car is just in the 'run' position?

It sounds like I have a wire shorted or something.

- Jim

[detobias]

if O2 sensor is cold, it doesnt put out a signal

so if you are reading anything when you turn 'key on' with engine off - you have a wiring problem

did you do my test above ? another trouble shoot step would be put your voltmeter on the signal out of the sensor (with it plugged in); see if the VOM and the A/F gauge agree.

[90Acclaim]

going to try it on my next couple days off.... which won't be until next Saturday

It's getting to work though, so that's the main thing.