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I just got done installing an AIR/FUEL gauge in my 90 GT and I'm rather baffled... Hooked up exactly as it is suposed to be, but all lights light up and flicker at all times. And as I rev the car they go off when they should be coming on....kinda opposite of what it should be.. any help?
Thanks
Jay
 

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Well, I don't know if I should be the first person to respond (I just came inside from installing mine!)

Mine did the same thing. don't worry though, until the sensor heats up to operational temp, it's gonna do that.
 

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The air fuel guage gives you a reading at WOT, when you put the pedal to the floor it should go a few bars rich. When you let off the gas, it goes blank and when you drive it constantly adjusts and gives you that nifty light show.
 

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Do air fuel guages run off resistance in the o2 sensor wire or do they actually read signals coming from it.

I ask because a couple of days ago i was running two bars rich now after moving my guages and rewiring it im barely running rich.
 

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I was wondering about that. I only get a solid reading at WOT. Other than that it constantly bounces up and down. I get nothing when the O2 sensor is cold.
 

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You must realize that this a/f gauge is really nothing more than a voltmeter that measures the o2 sensor's voltage (between 0-1 volts) and uses lights to display the voltage instead of an lcd screen. I wouldn't get too concerned with the absolute readings on this thing. Even the mazda workshop manual only specifies vague voltage ranges (.5-1 volt at high rpm, engine warm) to test the o2 sensor, so I really don't think this thing is that precise.
 
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It is important to have a very good ground for gauge accuracy.

The ecu runs in open loop mode until you are at WOT, it then switches to closed loop mode and runs off pre-calculated fuel values.

The ecu attempts to keep the o2 sensor at .5 volts at all times during open loop mode, which is why it jumps around so much.

I built my own A/F guage and mounted it where the ATX shift indicator is in the dash. It looks OEM : )
 

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FlySwat said:
It is important to have a very good ground for gauge accuracy.

The ecu runs in open loop mode until you are at WOT, it then switches to closed loop mode and runs off pre-calculated fuel values.

The ecu attempts to keep the o2 sensor at .5 volts at all times during open loop mode, which is why it jumps around so much.

I built my own A/F guage and mounted it where the ATX shift indicator is in the dash. It looks OEM : )
Too cool wanna show some pics?
How many LED's did you use? I like how Dawes's only uses 4 lights to make things simple, instead of 30000000 of them.
 
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