Just had one of these fitted. Lumenition (19 led) meter. Aware that when you floor it the lights should be in the green sector, (rich), and red being highly undesirable, (lean). Can someone explain what else i should watch out for?. The lights constantly cycle when the car is up to temp. I take it this is normal, but can someone explain what would be abnormal in the light sequence?. Any info would be appreciated. The car sometimes runs over the max power light well into the rich sector, is this normal too??.

cheers.

 

foot off accelerator should drop into red

 

When you're off boost, the ECu is constantly looking for a Stoich mixture, which is why you see it bounce from lean to rich. This is normal. I presume your meter is 0-1 volt, therefore it will bounce round that scale, but usually not fully to 1v. each incriment will be 50 mv if you have 20 lights. There is a guide on here as to what is a good voltage on WOT.

Abnormal behaviour would be the lights fading, or hanging in a constant place, off boost.

When on boost / or Wide Open Throttle (WOT) the lambda sensor is not used for engine control, and the MAF sensor is then used.

The AFR is only really useful on boost, (other than showing you have a duff sensor off boost) as it will show your mixture from the lambda.

Still a useful bit of kit.

MB

 

Thanks for the replies. So i am right in saying that on boost the MAF controls air/fuel mixture, so you could tell if your MAF was fecked on boost and your lamada was fecked off boost with the meter??

gregg

 

Yep.

Although last time I had a duff MAF, my AFR just went plain weird and got stuck in various places Someone may be able to explain a bit better, what the MAF does off boost.

MB