does anyone know which wire i can plug my air fuel gauge into on the CPU? i heard it was a solid grey, but i dont see a solid grey on the plugs that go into the CPU!! the manual says that the o2 sensor wire that goes to the ecu is a green/yellow wire... does anyone have a picture of which wire they tapped into to get my a/f gauge to function properly?? i have an 87 T2. thanks guys -jacob

 

You should be looking at the ECU (in the passenger footwell), not the CPU. It's the gray wire on the 18-pin plug, bottom row (clip on top), second from left (looking at the back of the plug).

 

i was looking at the ecu, i just had them confused. thanks bro, i'll go give that a shot. be back in a minute

 

i have no grey wire in my middle plug (the 18 pin one) so we tried the blue/yellow stripe wire that was in the place of the grey one you were talking about, and the a/f gauge was pinned all the way at the top so i dont think thats the correct one, and it didnt move when i hit the gas and didnt bounce. do you think that it may be a problem that i dont have a grey wire? and there is a black wire second from the RIGHT that we got a solid reading on the a/f gauge from on the 18 pin plug. do you possibly have a picture of your harness that i could look at? and are the wires different colors for the s5 T2's? just making sure that you werent thinking about the s5 ecu instead of the s4 if there's even a difference. any other ideas?

 

and when you said looking at the back of the plug did you mean the side with the wires or the side with the copper connecters that connect to the ecu? (that would be the problem if we were looking at the wrong side of the plug, but the wire looks black and not grey) we tried that wire before and we got a solid reading from the a/f gauge in the middle slightly above stoich. please let me know if we were looking at the wrong side of the plug bro. thanks. -jacob

 

Yep, you were looking at it the wrong way. The back of the plug is the side with the wires coming out. The 88 wiring diagrams say it's a gray wire, but the 87 may be different.
It sounds like you've got the right one now, just remember the O2 sensor has to be hot before you'll get a proper reading.

 

ok great man, appreciate the help. we'll give this a shot and go for a little drive and see what happens. thanks -jacob

 

everything works great now, it ended up being the wire you were talking about, we were looking at the plug from the wrong side. thanks for the help.

 

So did you end up using the black one? Or the Blue/Yellow one?
The one I circled here, or no?

 

Does this apply to a 88 n/a aswell? Are there any differences with colour coated wires?


Pic courtesy of www.1300.com

 

Ya, thats N/A also .. but thats for the S-AFC, that doesnt show the position of the O2 sensor

 

hold on a second, i'll go look at that and get back with you.

 

all of those diagrams are wrong. its the middle plug. second from the right side on the bottom (black wire) 2d i believe? not sure about the 2D thing, but its the second from the right on the bottom, black wire.

 

Oh, I guess, on a side note, I should have stated to disregard the wriitings on the diagrams but to use the pic for reference Instead.

So 2D would be the O2 Sensor wire? When I hook up my A/F Gauge, I plan to us the wire at the ECU rather than at the O2 Sensor wire Itself.

 

Ya, i got it figured out ... seems to work great. I installed my S-AFC at the same time... I wish i could have done My Boost controler also .. but i have to wait to smog first .. S-AFC looks damn cool, I haven't made any adjustment .. nor do i really plan to until i finish the break in.

 

What's wrong with the air/fuel guage if it reads everything backwards? Is there a wrong connection or something or something hooked up backwards?

autometer phantom air/fuel

 

here

 

Nice that should have been up here long ago.

I will tell you one thing, the wire is NOT grey, and NOT Green/Yellow. Its plain as day black.

 

Where could I find an ECU pic with the description of ALL the wires leading Into It? I'm surprised that It hasn't been posted yet.