10 replies to this topic

[andyt]

Hi Iam thinking about possibly fitting an Afr gauge to my 91 mg metro engined mini so that I can have a better idea of the fuel mixture whilst driving the car, has any one got any experience or tips on fitting one and also which kit to buy.
Thanks Andy.

[Ethel]

I got mine as a kit from 14point7.com

 

Being able to data log will be really useful if you intend to use it as a rolling road alternative  and  avoid driving in to ditches (wouldn't want the Prime Minister to get squished  )

 

There's a bit of a discussion to be had about where best to put the sensor. They do say about a metre from the valves is ideal, but as A Series inner & outer cylinders will give different readings there's an argument whether you want to sample the lot or just a pair. I didn't really have that option with a turbo. You can buy threaded bosses to weld in on Fleabay - it's best to have the business end of the sensor pointing down a bit for drainage.

[Steve220]

Take head of the recommended lambda positioning.

[unburntfuelinthemorning]

I bought a Dynojet Wideband Commander about twelve years ago for a different vehicle which I've just fitted to my Mini.  It works really well.  Really simple installation too, the hardest bit is finding a place to put, and fitting the O₂ sensor but it's not that bad.

 

 

[andyt]

Thanks for the replies, is the wiring fairly simple? is the lamda best placed just beyond the y piece the?

 

Andy.

[unburntfuelinthemorning]

I put the O₂ sensor just beyond the Y piece so it would get the average ratio from all cylinders combined. 

 

The wiring was one ignition live, earth, one to the sidelights for illumination and then the included pre-wired lead to the sensor.

 

There's more wiring for the other features like the data logging but I'm not using that.

 

Installation instructions

[Pete - W.Sussex]

Another tip from my experience - not with a Mini I stress - is to be careful with the ignition wiring. You want the O2 sensor to switch on when you start the engine, not on position 1 running stereo etc. The lambda heats up when it is first switched on and if it is heated much before the engine fires it can be damaged by ‘cold shock’ on the initial blast of exhaust gas when the engine fires. Ask me how I know!

 

It’s about reading the instructions of whatever kit you get carefully - my experience was with an Innovate system, others may vary I suppose but the point is lambda sensors are more sensitive than you might think, hence the comment above on positioning to avoid condensation getting at the heated element.

[Dannyboolahlah]

I got a boss welded into the Y piece of my LCB manifold like above. Managed to get it just above 90 degrees to avoid condensation getting to it. Wiring comes through with the reverse light switch I think.

[croc7]

For the power source, I used the parking light tab on the headlight switch. That way you can start the car, then turn on the AFR/sensor using the light switch. Seems to work OK.

[Ethel]

You could switch the supply with the oil pressure switch to ensure the heater only runs if the engine's starting.

[Ethel]

You could switch the supply with the oil pressure switch to ensure the heater only runs if the engine's starting.