Air/Fuel Ratio Gauge Question?

Pin 43 (Dark Blue/Lt Geen wire) or pin 29 (Dark Green/Pink wire ) on the computer

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

The A/F gauges that use the O2 sensor signal will jump all over the place. The reason is that the O2 sensors "switch" between .2 volt lean and .6 volt rich with a curve that looks like the drop off a high cliff. The curve is almost straight up and down, so the voltage shoots from .2 to .6 and back down again 2 or more times a second at cruse.

i hooked mine to the black wire on the o2 sensor. works good for me

i did what whitemustang89 did and hook mine up to the wire on the 02 sensor

If you installed it correctly and....

" my gauge hops up and down and doesnt show it running rich at all even though its supposed to when its cold, right..."....PRO5090GT

What is supposed to happen is that upon initial cold-start conditions, it will immediately drop off the scale in the lean, then within a few seconds it will drift into the rich, kind of bounce a little, then once the O2 sensors warm up and the engine switches into closed-loop operation it should bounce in the mid-range...sometimes a little lean, sometimes a little rich. When you hit the gas, it will go rich. When you let off the gas quickly, it will go lean.

This is all assuming that all sensors, solenoids, computer and what-not are working properly, proper tune, adequate fuel delivery, and so on. Too many times people are posting that those A/F ratio meters are a POS, not understanding that all it is is a voltage meter with a pretty light display. So if it isn't reading the O2 sensor voltage you think it should, then perhaps there is something wrong with the sensors or your tuning.