building an air/fuel monitor

[bodger]

http://www.scirocco.org/tech/misc/afgauge/af.html

just wondering if anyone had built one themselves ?

they are loads of money to buy ...but cheap to make

[Quagmire]

This is for a NB sensor right?

I thought that they literally only measured lean vs rich, and that you cannot infer any particular mixture other than stoich from one?

[DaveEFI]

http://www.scirocco.org/tech/misc/afgauge/af.html

just wondering if anyone had built one themselves ?

they are loads of money to buy ...but cheap to make

A narrow band one isn't going to be much use. I challenge anyone to build a wideband one for less than the cheaper commercial offerings.

[bodger]

This is for a NB sensor right?

I thought that they literally only measured lean vs rich, and that you cannot infer any particular mixture other than stoich from one?

only need it as a monitor for LPG running ...
ive already got 0-1v sensor fitted ... so just need to read the output from that to make LPG is running about right ...

[bodger]

how can you tell narrow from wide band sensor ...
ive got a choice of 2

1 is a 3 wire titania
1 is a 3 wire zirconia

cheers guys ...
theres a few air/fuel meters on ebay .,£65.00 inc post

[DaveEFI]

Wideband generally have a heater and something like 6 wires.

[bodger]

Thankyou Dave

[Baracus]

i built one similar to the link, absolutley bloody useless.! They pretty much act as a switch, either rich or lean and it's pretty much impossible to gain any useful information from them.

[bodger]

Thankyou , thats interesting .....

there seems to be quite a few on ebay for about £20
anyone had any experiance with them ..?

i dont want to control anything and im certainly not going to spend £300 on one , all i want to do is see how the LPG Is mixing ...
ive got a gunsons exhaust gas thingy but its no good for when driving about ...
LPG can change so much when drving i want to see whats happening

[stevieturbo]

£150 buys you a brand new wideband complete.

Really, wouldnt even bother with anything else.


If you want to use a narrowband on a budget, just stick a digital voltmeter on it and watch that instead. It's basically free if you already have a voltmeter.

When you say you want to ensure it is mixing ok....exactly what do you mean though ?

[bodger]

i just want to see if its rich or weak as im driving ...
ive already got a lambda sensor so just want to read it ...


dosnt have to be seriously precise , as i say ive got a gunsons exhaust meter thingy .. but it changes so much under load ... not worried about tickover ...i can get that about right ..,
its driving around i want to get about right ..
it never runs on petrol , so its only getting the power valve set about right on LPG ....

theres a few meters on ebay for about £12.00

[stevieturbo]

i just want to see if its rich or weak as im driving ...
ive already got a lambda sensor so just want to read it ...


dosnt have to be seriously precise , as i say ive got a gunsons exhaust meter thingy .. but it changes so much under load ... not worried about tickover ...i can get that about right ..,
its driving around i want to get about right ..
it never runs on petrol , so its only getting the power valve set about right on LPG ....

theres a few meters on ebay for about £12.00

Rich or weak compared to what though ?

Mixture will vary under different driving conditions. And a narrowband is only accurate at stioch. So in a normal closed loop system mixture will always switch either side of this.
So you would see richer/weaker than stioch all the time.

Is this an injection system ? gas ring type ? What control over mixture do you actually have ?

All you need for a normal 2-3-4 wire sensor is a 0-1v digital multimeter

If you're adamant about some flashing LED's instead via a narrowband sensor

http://www.jaycar.co.uk/productView.asp ... rm=KEYWORD

http://www.jaycar.co.uk/productView.asp ... rm=KEYWORD

http://www.jaycar.co.uk/productResults. ... MIT=Search

Now despite the heavily non-linear response of a NB sensor, as long as you understand and accept that it is not accurate. It can still be usable and give some reasonable indication of mixture.
So if you really dont want the expense of a full wideband, then something like the above would be viable. Just dont try tuning anything performance related using one ( although I have done many years ago before widebands were available )

[bodger]

Thankyou ...
its not performance im after , just want to if its weak or rich really ...
more about not using too much fuel ....lol

its a BRC reducer and mixer ring and screw type power valve ...
ive already got a 3 wire Zirconia sensor fitted ...

the LED row display looks good to me ... fitted in a small box ... sounds good at that price ...

[bodger]

do they sell those kits anywhere in the uk ?

by the minimum order of £10 + £5 postage
its cheaper to get a compkete gauge on ebay ...
thats a shame ..i like the led one

[stevieturbo]

do they sell those kits anywhere in the uk ?

by the minimum order of £10 + £5 postage
its cheaper to get a compkete gauge on ebay ...
thats a shame ..i like the led one

Jaycar is Aussie, although that site is .uk

I bought some stuff a couple of years ago, it arrived promptly, and postage was cheap.

Although what I bought was a little over £20