AFR Gauge help

[quequieresvonmir]

I just finished installing my AFR Gauge 30-4110.  The Gauge works fine but I believe needs to be calibrated according per instruction.  I know how but I wouldn't know what to look for.  The Gauge is in default position P0 and shoes 14.5.  In case I need to calibrate do I disconnect the 02 sensor or leave it connected?

 

TIA  

[TobyB]

Typically, 'calibration' is done in free air, everything connected as

it will be when the car's running, but using atmosphere as the test gas.

 

But that procedure you show is just changing the behavior of the gauge, not  calibrating the gauge to the sensor.

 

If you're showing 14.5 with the engine not running, something's up with the sensor, the wiring (kinda unlikely) 

or the gauge.  

Me, I'd give AEM a call or a chat.

 

t

 

[jimk]

Bosch LSU 4.9 is calibrated at the factory and does not need any more calibration.

Bosch LSU 4.2 has the free air calibration. 

The data sheet is for when the controller is outputting a 0-5 V signal to an ECU.  The gauge needs no calibration.

[quequieresvonmir]

Thanks Toby, Jim. 

So when the car idles it shoes anywhere from 12 to 13 which is to rich, correct?  In order to screw around with the mixture screw, car idling do I leave the sensor always connected or disconnected?

[jimk]

Leave sensor connected.

Keep your free hand on something attached to the engine and you will feel (as you turn in the screw) when the mixture is leaner than best idle.  You may not be much leaner than what you see. on the gauge at best idle.

[quequieresvonmir]

Ok Jim, thanks. I forgot one thing, the last picture shoes the wiring.  The white wire is not connected yet, since I got everything covered up with the under dash panels what/where would be the easiest way to connect the white wire, any idea?  That would be all.

Thanks again for your help

[Stevenc22]

13:1 at idle and 12:1 under load is perfect for these cars. Modern cars try to hit 14:1 for efficiency purposes.

Edited December 6, 2023 by Stevenc22

[jimk]

The white wire is feed to an ECU.  From the question about idle mixture, I understand that you are not using an ECU, so leave the white wire disconnected.

[quequieresvonmir]

No ECU Jim, so I'm good then.

 

Thank you all.