Cret

My new AFR gauge (autometer/autogauge) that I fitted a few weeks back now seems to be playing up for some reason, either that or my car has drastically changed it's mixtures since then somehow.

It was working fine for at least a couple of weeks, but recently I've noticed that whilst it lights up and sits in stoich when I start the car, the moment I slowly begin driving off (even at a slow trundle) the lights slowly go round to lean then disappear so that when I'm actually driving (easy or hard) there are none lit!!

I'm not sure if the gauge has buggered up somehow because I suspect if the mixture on the car had drastically changed to be so lean no lights are on I'd notice a difference in how the car drives, and also that such a lean mix would be making the knocklink go insane.

The O2 sensor was replaced with a new one st the same time that I fitted the gauge so I'd be surprised if that's just suddenly knackered - has anyone heard of that happening before?

Any ideas?! Cheers

bigunit

Got the same gauge m8 mine sits at stoich when started for about 30 seconds then flickers from lean to rich when warmed up on tickover, when driving it flickers all over the place but spends most of the time at 3/4 stoich and just into rich. only at WOT on boost does the gauge stay steady at 3/4 rich...
From what i have read i would say bad connection possible that the earth is poor Have you gone to ecu or o2 sensor?

Cret

It's wired in where the sensor wires plug in at the front right corner of the engine.

It's possible of course but if it was a wire that had developed a dodgy connection I wouldn't expect it to do exactly the same thing each time I drive it like it's doing.

bigunit

Yes i see what your saying m8 but we are talking a very small voltage and if the earth is not spot on it can make it do stupid things....
b4 you had the problem did it react the same as mine?

Cret

For a couple of weeks or so after wiring it in it would generally stay in the stoich area and would move from lower stoich on easy driving towards rich with foot down but never really going into rich. With decelleration it would dance around & then go off which I believe is normal.

I'll check all the connections I guess & see how they are, or maybe even connect it up by the ECU instead.

wintn

I had a similar thing with my Dawes AFR, turned out to be the Lambda sensor.
Could be connections though, I was recommended to solder the sensor wire and take the earth to the main body earth be the battery. A small increase in resistance can make a big difference.