has any body fitted a AFR gauge that isnt running an 02 sensor for there engine?

as im on bike carbs i have no need for an 02 sensor for the ecu.

i have a 3 wire universal sensor and a AFR gauge i got on ebay new

eBay Item

eBay Item

the gauge has 3 wires, red goes to +12v, Black goes to Earth, Green goes to 02 Sensor

the 02 sensor has 3 wires the two black are the heater (+12v IGN & Earth) and the white goes to the ecu for the sensor and the sensor then earths through the exhaust.

so the green wire from the gauge just joins on the wire from the ECU so the ecu still gets a signal, but i dont have it going to the ECU, it isnt connected to anything.

So how do i wire it in?!?!?

i pressumed the green wire would be a positive and earth through the sensor but it is not as i tried just earthing the wire through chassis and nothing happened so i touched it against a fused 12v feed and the gauge went up so how does that work!!!

so in a standard set up the green wire would piggy back off the feed to the 02 sensor and as the sensor is the heat variable resistor then the green wire would just get a constant flow as the feed from the ecu would earth through the gauge rather than the sensor and the ecu would think it is running really rich and back the fuel off and the engine would run like a bag of shit? how does that work???

So basically can someone try and help me wire my gauge in?

Hi,
the green wire from the gauge goes to the lambda censor (white wire) fitted in your exhaust, that's how mine works if I remember correctly, (car is outside under cover at mo) these are a bit crude, but gets you in the right ball park, should go on a rolling road to confirm mixture etc, these are know as narrow band, what we realy need is wideband afr. I can confirm wirring at weekend if you have no joy.

Andy

okay lovely cheers mate, yeah i know about wide band as we use them on our cars at work but i just wanted to something to get it about right

I doubt you will be able to tune your carbs using a narrowband. I tuned mine with a wideband and needed the range from about 11 to 16, a narrowband will only measure from about 14 to 15.4.

An O2 sensor produces its own voltage on the output, an AFR gauge (narrowband) is just a fancy voltmeter.

Unfortunately a narrowband will be of limited use to you as it will only tell you whether you are richer or leaner than stochiometric, but not by how much.

ill have a shot at getting it set right at the weekend if not i will get a wideband sensor from work and set it right

thanks for the quick replies

Correction the two white ones are for the heater I think. And the black one is for the gauge...

Does the heater need to be on a timer or anything or just constantly on?

Narrow band sensor heaters can be powered from the switched ignition circuit. They are self regulating, so draw fairly low current when the engine is running and they are up to temperature.