Fuelling and Lambda
Turbo Mini Forums

I'm really getting pissed off with my fuelling and Lambda.

It's only narrowband, but good enough for what I want. The display has the following lights: 3 red (lean) , 3 Yellow (lambda =1) three green (rich).

But no matter what I do it never gets out of red. At tickover I can richen up the mixture until the car is choking and then back to a point where the mixture is so lean the engine nearly stops, but the gauge just reads lean.

Either something is buggered or (and this is what I'm thinking) the sensor is connected up backwards.

To help me out, on overrun, would you expect the mixture to richen up or lean out?

I know this makes me sound thick, but using the lambda has always just been a backup for my ear and how the car drives, but it seems to be telling porkies (especially considering the sooty exhaust!)

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

I would check for air leaks first. The slighest wiff of oxygen and it will read lean - I think.

Is the gauge set up correctly? Somewhere along the line it has to convert the signal to volts to drive the meter.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

on the overrun it'll lean out. if its popping and banging through the exhaust thats one way to tell if its too lean.

at least thats what i've found with mine anyway. (wideband)

Make sure the exhaust isn't blowing anywhere before the lambda, especially where the downpipe clamps to the Turbo this will affect the readings.
As Bud says, it should go to lean on overun.

WWW.TURBO-MINI.COM

Lambda is on the elbow, so deffo not blowing before then.

I've swopped the wires over on the sensor, I see what it doe in a bit.

It leaned off on overrun with the sensor connected as it was though, so I fear it was right.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

If its a narrow band you can test it, I think you just heat with a propane torch and check the voltage coming out, about 0.8v I think--google it.. If its buggered it would show lean all the time..

Terry

website:- http://www.terryhunt.co.uk

Heres one..

http://rover800.gaima.co.uk/Rover800/www.p...tech/lambda.htm

website:- http://www.terryhunt.co.uk

2 whites to 12v pos and earth ,black to sensor ,if theres another wire then that goes to earth too , check all earths are really good and sound .maybe a duff sensor ?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

I'm thinking a duff sensor.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

plus Narrowband AFR metering is dodgy at best.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Yeah, I understand it's limitations, but I got it all before wideband was readily available at a decent price, jut not used it for years.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Stick a digital multimeter on instead and see what its reading, and how it responds when driving.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will