Hi all, I own a stock 1990 Rx7 T2 which seems to have a bit of a problem. I was fixing an Exhaust leak Today and noticed the lead of the 02 Sencer was broken on the car side of the plug. That is not a problem i thought, but it is as i can't find the other half of the wire.

Does anyone know where it comes out of the loom? or a good place to look?

 

I think it must come from under the Inlet but i dont want to take it apart if it doesnt come from that part of the loom?

 

You mean, the actual part of the wiring harness that connects up to the o2 sensor is missing? hmm...

It's BEHIND the engine...above the transmission. Has a green connector, i believe.......maybe yellow. maybe it's just lost.. If you find it, i'm sure you could just splice a bit of wire into it, and it would be fine...

-Tesla

 

So its round the back of the engine? Does it run under the Inlet Manifold with the Injector wiring?

 

If you want to find that lead you are probally going to have remove the upper intake manifold to find where that lead comes into the wire harness.

It runs by the primary injectors under the upper intake manifold. You can try this which would be easier than pulling the manifold. You could pull up the carpet and remove the metal cover from the pass. floor board (Where the pass would rest their feet..where it slopes up). Then you see the ecu. I can tell you the wire to cut. Once you find the wire you put a new wire on your O2 sensor and run it through the fire wall straight to your ECU. I ran my wire thru the AC drain line. Not through the line but through the grommet.

Then you just connect the wire from the o2 sensor straight to the wire into the ECU. I don't have my wiring diagram so I don't know what wire it is.

However, it worked for me. Good luck

James

 

Do you think this will cause a lack of power and masive loss of Mpg?

Becouse i have been doing around the 10 Mpg mark and it does'nt feel right.

I supose this might cure it. Can i check the O2 sencer to see if it works?

 

On a 86-88 You can put your meter on the ECU, pin 2D, the middle plug, bottom row, second one over from the right, Gray wire. Driving at a steady 60-80mph in fifth should give you a voltage reading that constantly jumps on either side of .4V. You'll see figures like .3 then .7 and then .1 and then .6 and on and on. You get the idea. When you stomp on the pedal you'll get a constant voltage reading of something on the order of .7 to .8v
EDIT: Or you could make a diagnostic bug lite assy for less than four dollars that will flash whether or not the 02 sensor is working. It takes all of 30 minutes to make. RadioShack has the two leds involved. You can string the wires from the green connector on the left hand strut tower to somewhere near your insturment cluster. This is the site: http://home.rmci.net/panther/ecu_codes.htm

 

Location of O2 sensor wire on T2s: Comes out of loom at same location were the connector to the BAC valve exits the loom. You do not have to remove your intake, you do not have to rewire your entire car.


Later,
Douglas

88 Turbo II
Melbourne, FL

 

The Only wire that i can find that is loose is Green/Black and comes out of the loom at the ft of the IC next to the Turbo - Ic pipe.

Does this sound right?

 

Yup that sounds right.

Can't guarantee the wire color though, mine is all encased up in electrical tape and silicon glue since I fixed it a while back. But on mine it did come out of the loom by the Turbo IC pipe along with the connector to the BAC valve. So as long as you don't see several other loose wires in the same location then it sounds like you have it.

Later,
Doug

88 Turbo II
Melbourne, FL

 

This site http://www.fc3s.org/ and under MANUALS has the location of the 02 sensor on a 89 model. Its pin 2C on a 89 and probably 90model also. On a 86-88 model, the 02 wire is a gray shielded wire. I would have expected the same on a 90. I suggest you ring out that wire you found from that end to pin 2C before wiring it up.