i got an air fuel gauge the other day and wired it all up at the ECU. i started the car and the gauge didnt show any reading, i figured the O2 sensor had to warm up, i wait a few minutes and still nothing. i take it for a little drive and it does light up while acclerating and crusing but when i come let off the gas i get nothing again, i know that it is supposed to go lean when you let off of the gas but it doesnt even light up lean on the gauge. from a stop if i floor it all the way to 6000 rpm it never goes more than 1 or 2 bars into rich, i thought rx7s ran super rich. while just crusing at a steady speed it goes from full lean to just before the first rich light, i know it is supposed to bounce back and forth, i just have a feeling its supposed to go more into rich. i replaced the O2 sensor today and still the same results, only now gauge doesnt show anything sometimes when just crusing and other times it is bouncing back and forth. could i have some clogged injectors or bad pump?

 

Are you absolutely sure you connected to the right wire at the ECU?

 

You could also have a ground loop. I would try and run an added ground wire to the O2 sensor (1 wire?) and see if that helps. We typically use a spade or open-end (i.e. "fork") connector with NO INSULATOR and use a band clamp on the O2 sensor housing as far away from the exhaust as possible.



-Ted

 

I thought you where supposed to wire the a/f ratio guage to the o2 sensor? I didn't know you where supposed to wire it into the ecu?

 

You should wire it to the O2 sensor wire at the ECU end, not at the sensor end. This avoids disturbing the shield wire and grounding the signal.

 

Yeah, sorry about the confusion. The AFR gauge ground should be common to the O2 sensor ground. 1-wire O2 sensor grounds through the housing, so you need to secure the added ground wire to the O2 sensor housing.


-Ted

 

wow didn't know this, which one is the o2 ground at the ecu? Thanks.