Oxygen sensor question?

[Kev@carnoisseur]

I want to fit a Air/fuel ratio gauge to my 89 Esprit turbo SE. The instructions say I have to cut in to the 'signal wire' from the oxygen sensor. Trouble is I dont know which one that is? and if I get it wrong it will kill the gauge!! Does anybody know which one the signal wire is??

[ruff]

Hi!

Let me give you my 2 cents.

To find right 'signal wire' for oxygen sensor,first you need to get the E.C.U. diagram.
The E.C.U. diagram will tell you the 'wire' that controls oxygen sensor .

ruff

>> Edited by ruff on Sunday 21st December 14:35

[stevenM]

i think for an A/F guage to be any use to you then you'll need a wideband sensor

[NJGSX96]

You need to find a wiring diagram for the ECU. Splice into that wire instead of the ones at the O2. Do you plan to get one of the cool looking blinky gauges that does very little ( www.diamondstarmotorsport.com/autometer.shtml ) or are you getting a full digital readout like Jumptronix offers ( www.jumptronix.com/index.htm )? Another choice is the Apexi turbo timer and AF gauge. pretty slick really.. www.roadraceengineering.com/parts/apex/apex-tt-allparts.jpg
If you want it for functionality more than a "cool factor", I suggest getting a wideband. There are many to choose from and the price varies as well. I noticed on my 94 there is a second bung for another O2, perfect spot for the wideband. They come with logging capabilities and can be attached to a gauge as well. Pricey, but fully functional.

Rich

[lotusguy]

Hi,

I believe that the SE's use a three-wire lamda sensor. One wire is for the signal, the other two are for a small heat coil which heats the sensor up to operating temp faster so the ECU begins proper management sooner. Usually the heater wires are red/black while the signal wire is often blue, white or light blue. This is the wire you want to splice into. Happy Motoring!...Jim'85TE

[roadburner]

Hi,
the oxygen sensor of my SE got 4 cables.1 red one,2 black ones,1 white one.

[lotusguy]

roadburner said:

Hi, the oxygen sensor of my SE got 4 cables.1 red one,2 black ones,1 white one.

Hi,

Ok, 4 it is. Take the connector off the sensor and check each one with a multimeter. The one with the low voltage output (<1.5V) is the signal wire. I suspect it will be either the white or the red one. Happy Motoring!...Jim'85TE

[numbnuts]

take a multimeter place black to earth use red to probe each wire your looking for a reading alternating from 1-5v usually.
engine must be running at normal tempature.
hope this helps.
if not fit a single wire oxygen sensor as well and use that one.

[dr.hess]

The two wires the same color are likely the heater. That leaves 2 wires left: the supply and the signal. The signal wire is usually shielded, so look for the one with a braid around it under the insulation. Probably the white one. Read:
[url]http://home.flash.net/~hess/Clip_n_Saves.htm#Oxygen%20Sensors[/url]

Dr.Hess