AIR/FUEL ratio mixing project!

Post Wed Nov 02, 2005 5:07 am

I know there are specialized third party gadgets to monitor air fule ratio mixing.

I would like to know has any one tapped in to Motronics 1.3 ECU and picked up this info and display in the form of LED's or Guage Meter in the dash board?

I would like to continuesly monitor this ?

TQ

Post Wed Nov 02, 2005 8:24 am

Would of the thought the existing economy swingometer gives a pretty good indication. The only control you have over the mixture whilst driving is your right foot and gear selection unless you have someone in the passenger seat with a laptop attached to the ecu.

Post Wed Nov 02, 2005 8:49 am

afaik it's a case of lambda sensor connectec to some kind of display. A volt meter would do but you could use anything. There's an autmotove company in Austrialia who seem to do quite a few projecdts like this, maybe they have something. Let me know what you find because I'm going to me making my own one soon so will be interesting to see what you come up with.

Just found this...

http://autospeed.drive.com.au/cms/A_0217/article.html

Post Wed Nov 02, 2005 9:10 am

Most E30s are open loop fuelled, and don't have any kind of fuel mixture monitoring devoce on board.
The least you will need is a lambda sensor fitted in the exhaust, and these only really show if you are lean or rich.
There is a newer and much more expensive type of lambda sensor available now, known as a wideband type, but I'm not up to speed with the tech details of these. From what I do know, these should be a better starting point for an air/fuel meter,

Post Wed Nov 02, 2005 5:59 pm

Wideband seems to be the way forward. they're used in professional afr meters such as the LM1 (on ebay for about 250quid). I'm not sure what the dynamic range of normal sensors is (in terms of how far lean or rich it will go). I know alot of cars run open-loop when the are under load so just use a normal sensor for cruising.

As brian said, you've not got a sensor on your e30 (very unlikely anyway) so you'll need to fit one. If you fit one with out a heater (one or two wire versions) then you need to fit it on the manifold to get it up to operating tempreture. three and four wire sensors have a heater so they can be fitted further away. I'm not sure how the placement affects the operation though.

My father priced up a wideband sensor at about 75+vat and that's trade price. They do go on eBay but I've been reluctent to order one as I don't know part numbers and don't want to get ripped off.

As I said I'm going to be knocking something up for myself over the coming months so I'll let you know what I end up doing. Although I'm not sure if mine will be a permenantly installed jobbie as I only want it to get the fueling right for my pie-in-the-sky MAF project.