A/F Meter problem
 

I am installing a Air/Fuel Meter in my 82' 12a carb, welded the bung on and went to test the meter, It show a single led on the rich side, and does not move at any RPM, I did let it get nice and warm but with no change. It is the Autometer brand SportComp 2' 1/16. I went down and purchased another sensor and it did the same thing. The sensor is a single wire model.

Any ideas??????

The issue you are having is no signal from the O2 sensor to the guage. What exactly did you have to weld? These guages are meant to just tap in to existing factory wiring. IIRC there should be 3 wires that come from your guage : 1 red, 1 black, 1 purple. red goes to switched ignition source, black goes to ground(use a GOOD ground!) and purple taps in to the factory O2 sensor wire. Check to be sure you have positive connections at any splice points, use Only the same guage wire as what comes out of your meter. This is important because you want a clean clear signal that will not provide excess resistance in the current flow to both your guage signal and the ECU signal. Lastly, the meter should read rich while the car is warming up, then it should cycle between lean and stoichiometric at idle. After depressing the accelerator it should go from rich to lean and back to stoich. Usually it takes about 7 minutes for the O2 to really reach temp. This includes warm-up time. HTH

while its not probabale that the guage is bad, You can test the sender directly with a digital volt meter.

Did you solder the connection or crimp it? Do not crip as steted before you need a good connection.

put a grounding strap on your exhasut somewhere, it sound slike a bad ground. You would think that you would get a good ground through the block but a lot of times it doesn't work that way. Gaskets sealers, locktite, anti seize on threads these all conspire to not give a ground for the 02 sensor.

kenn

Kenn, never thought of that. Its a good idea!

The grounding of the exhaust is sounding like the best place to start. this is a 82' with a carb, no ECU. I will also make sure to solder the connector and not crimp it.

Thanks for the great input!!!

Well I had enough time to ground the exhaust at the section with the bung and still no change. I will check the other connections tommorrow......I'm at work now.

Maybe it's just running too rich?
What O2 are you using? If you're using a heated element one make sure you're tapping the right wire. Could be bad sensor?