air/fuel ratio gauge problem

spoolin_supra

New Member
Sep 29, 2008
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New York
Okay so I wired up my auto-meter boost and air/fuel ratio gauges today. Boost works beautifully but the air fuel/ratio no so much. It powers up but when I go to start the car it starts between lean and rich then imediately drops to lean and then shows no reading at all. There is three wires on the guage, power/ground/purple wire. The purple I tapped into the o2 sensor on the exhaust elbow. The only thing I can thing of is that the o2 sensor is shot but i dont think it will be givin me a reading on start up if it was broken. PLEASE HELP!!
 

rawmk3

New Member
Jul 5, 2008
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IL
Mine did the same thing. Its a matter of the gauge being set up for a wide band, not OEM. Cause i tapped into the Blue signal wire, and grounded the gauge to the frame, then tapped into the ingition for power and mine would do the start up display then drop all the way to the rich side. As I would get into upper RPM it would light up brighter, but never moved up off full rich. So it was either the fact i have a 3" exhaust, or it wasnt reading the O2 gauge right. The gauge worked tho, cause it was tested on another car too. So im guessing it was a matter of my auto meter gauge being for a wide band not OEM. But that is only my guess off what I came across. All the lines were hooked up correctly according to the diagram, and I had a local speed shop check it as well. They suggested a wide band and test that. So i'll get one when I put in my maft pro.
 

grimreaper

New Member
Jul 2, 2008
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Dallas
Stock o2 is narrow band, USELESS for tuning(limited even then unless standalone). raw, your using a piggy back after all your posts about how your car is gonna be this and gonna be that? Seems very ass backwards.

STOP adding in what you are doing/plan on doing in your posts, it solves nothing and helps nobody.

**knowing what the ecu is doing in closed loop is VERY informative, you just need to make sure your not tuning off narrow band and understand what your seeing.**
 
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grimreaper

New Member
Jul 2, 2008
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Dallas
That is correct. Does the gauge actually have numbers or is it a three section one from rich, stoich, lean? Did you tap into the wire or cut it completely and hook it only to the gauge?

Do you have any type of miss fire at idle, or stumbling when you blip the throttle after its idling lean according the gauge?
 

spoolin_supra

New Member
Sep 29, 2008
11
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New York
i cut the wire and 3 way crimped it, the guage is a 3 section gauge and the onl reading i get is when i am pushing my push button start to start the car then it reads nothing
 

rawmk3

New Member
Jul 5, 2008
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IL
Grim, my car is in build phases right now. Im in the process of upgrading from stock, which is why I said what i have said here. I was using a stock o2 on a stock engine except a full 3" exhaust. And my gauge was connected thru a Y type connection to the blue signal line. What I am doing is swapping it over to either maft pro, or standalone with a wide band. With stock components all it would do is power cycle and then sit on rich until it got into upper RPM ranges. But the light was very dim, and as the rpm's increased the light would get brighter. But never moved out of the RED. Infact it never moved off the far left at all. Just brighter and dimmer. hooked it up to another car and its clip, and it worked just fine, so it wasnt the gauge either.
 

spoolin_supra

New Member
Sep 29, 2008
11
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0
New York
I just tapped into power in ground that i found back there...i think its the same that powers like the stereo or something...they should be adequate because the boost gauge is run to the same power. I am stumped right now all I can think of is that the o2 is busted.
 

rawmk3

New Member
Jul 5, 2008
170
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IL
I had tested it on a car with a wide band, but no I have yet to find any switch for 5v-10v. I have tried a Faze gauge too, and it didnt work either. So I am pretty sure it was because of the stock o2, but it doesnt matter to me anymore, as im going with the maft pro with wideband and lambda.
 

mk3dude

New Member
May 16, 2006
50
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Toronto
i was wondering is there a way to wire the wide band output signal to the apexi pen style turbo timer. because it doese have a display for the stock o2 sensor a/f but its a narrow band signal. so i was just curious if its possible to wire the turbo timer o2senor signal wire as well as the ground to the wide band wires in order to display the a/f which display on the maftpro.

Thank You