I have a problem with a newly fitted Air/fuel mixture gauge in the way that its flicking all over the place.... I alway thought it should stay in the orange LEDs when running ok and maybe go into the rich a little when the toe is down.

I had it fitted yesterday and its all over the place, keeps shooting down into the red (lean) LEDs and all sorts


Its fitted to MY99 uk car, could it be on the wrong wire from the lamda sensor? I had a look and there are 3 wires, 2 white and 1 black.... its conected to the black one.

Any ideas or is it ment to change and move around alot?

Walton

 

I'm not sure which wire you should be connecting to but its not uncommon to see fuel ratio's constantly fluctuating as th ECU is trying to find the best A/F ratio which is near impossible for any length of time hence it pass's backwards and forwards past the Lambda1 mark (I cant spell scoitch or what ever its called lol). It will get extremely close though.

I'm guessing this will be one of the narrowband A/F gauges you've fit using the standard 02 sensor? You really need to buy a good quality wideband A/F ratio gauge to get a reading that means anything. The only reading you will get with the one you have is the fluctuating A/F Ratio's and either rich signal on WOT or a lean singal on CT.

 

Your gauge will flick all over the place on anything but WOT in which case it should read rich.

Not really true - i had a cheap Autometer AFR which i bought just to fill the hole my boost gauge left - if it wasn't for this cheapo AFR not showing me that my car wasn't running rich on WOT, i would have never known my MAF was failing which it was :eek

 

...just re-read that ^^^ bit of a mouthfull, but you see what i'm trying to say

 

True. It will flicker all over the place (usually in time with the injectors pulsing) and then display Rich on wide open throttle.