I just got my air/guel gauge from summit. It is the autometer cobalt series. I got it hooked up but something doesn't seem right with it. I read the instructions and it says it is normal for it to jump around but mine will go up as far as it can go then it will go down as far as it will go while I am driving. Sometimes it isn't reading anything then it will come back again. If I slam on the gas it reads normal to just a little rich but if I am cruising it seems like is going crazy. If I have it in park it seems to work just fine but it only acts crazy when I am driving. Please let me know if anyone elses works this same way. If not please let me know how yours works. I have an 89 Firebird Formula 350. I have checked all the connections and everyone one of them is tight. On the O2 sensor it only has the one wire coming out of the sessor into the connection then one wire coming out. I hooked the gauge wire up to the wire after the connection. Please let me know if I have a bad gauge or maybe a bad O2 sensor.

 

Its normal for it to do that, our cars are not equipped with a wideband 02 sensor. IT jumped like that on my car, its normal.

 

Does yours completely cut out and not show anything while you are driving? That is what really bugs me about the gauge.

 

Mine does that exactly. Only measures when you are at 3/4 throttle or more. Doesn't really matter what it is when you are just coasting around keping speed up.

 

Mine Jumps around pretty much constanty..If I'm cruizing at about 45...and let off the gas....it shows nothing....but as soon as I tap the gas....it jumps around

 

I have the autometer ultra-series AFR gauge. The readings you are getting are NORMAL. It will bounce around like crazy, cycling up/down as the fuel injectors cycle on/off. The AFR gauge will completely drop off the scale at times often under long freeway cruising with no led's lit. If you were to hook up a diagnostic meter through the ALDL (assembly line diagnostic link) you'd see the same readings. I did have a case where my O2 sensor was not moving and it threw a code 23 for EGR. In reality the computer was just sensing the lack of the O2 reading varying. The same reading was showing up on my autometer AFR, but I wasn't noticing it. Since then the O2 has been working fine, no more SES or code 23 and again the Autometer gauge shows the AFR reading bouncing as it is supposed to.

Lon

 

I have the first A/F setup from Dakota Digital, it seems to read just like the O2 readings in Craig's scanner software. If your guage is cutting out completely it may be hat you have taken your foot off of the gas far enough to invoke DFCO (Deceleration Fuel Cut Off), where the ECM turns off the injectors while decelerating. as far as it swinging from max to min..it shouldn't swing that far, you should see it go from the 300mv range to the 600mv range.