sooty
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| posted on 11/8/08 at 08:27 PM |
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AirFuel ratio check- Lambda
I know most use a Wideband Lambda setup etc to check the AFR.
But I want to use a basic quick method.
I've read somewhere that you could use a basic Lambda and a Voltmeter to check the AFR with the voltage output.
What Lambda should I get. ??
thanks
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MikeRJ
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| posted on 11/8/08 at 08:30 PM |
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A basic narrow band sensor will tell you only if you engine is running rich or lean, you won't know by how much so it's not a very useful
tuning tool.
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sooty
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| posted on 11/8/08 at 08:41 PM |
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I don't want a large expense at the moment, so would a ColorTune do nearly the same thing.
thxs
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rusty nuts
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| posted on 11/8/08 at 08:46 PM |
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Narrow band lambda is better than nothing and with a bit of patience and common sense it's possible to get the engine running within safe
limits. Dave Walkers book on engine management covers using a multi meter , suspect he knows a thing or two about tuning.
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jambojeef
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| posted on 11/8/08 at 08:46 PM |
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You're right - its basic, but it will give you a broad idea of whats going on.
Any 4 wire lambda will do you - vauxhall astras etc have donated their lambdas to my cause but BMWs often have 4 wires. Check at lambdasensor.com for
part no.s
I prefer the 4 wire type since its placement in the exhaust isnt as crucial - it has a heater as part of the cell and so you can put it further away
from the exhaust valves and still get a pretty reliable reading.
The website above gives you wiring diagrams for each sensor type, its basically 12v, earth, signal and another earth. When you connect your multimeter
to the output wire "anything under 930-950mV at full throttle should be considered lean" thanks to A Graham Bell's forced induction
performance tuning so bear in mind thats for a blown engine so you could perhaps drop a little lower for a N/A engine but not much since the sensors
response isnt linear.
Geoff
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matt_claydon
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| posted on 12/8/08 at 07:35 AM |
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All lambda sensors are the same output-wise. It's just a matter of whether they have a heater or not and whether they have a ground wire. 4-wire
are best as they have a heater and don't rely on grounding through the exhaust.
Just connect the heater wires to 12v. And a voltmeter across the other two.
(around) 0v will be leaner than 14.7:1 AFR, (around)1v will be richer. You won't read anything in between as narrowband sensors switch very
rapidly from one extreme to the other.
You should use an analogue meter (with a needle) if posible as digital meters have a slow response time and will not show the rapid swinging between
0-1v when you are close to 14.7:1.
[Edited on 12/8/08 by matt_claydon]
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MikeRJ
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| posted on 12/8/08 at 08:20 AM |
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quote:
Originally posted by matt_claydon
All lambda sensors are the same output-wise.
Not quite true, there are two types of narrow band lambda, Zirconia dioxide based (most common) which actually provides an output voltage, this is the
type to use with a multimeter (must be a high impedance multimeter, so either digital or an analog meter with a FET input buffer).
Titania based sensors change resistance around the stoichiometric point. These are used on some Vauxhalls, almost all E36 BMWs, many of the Land
Rover/Range Rover V8s, and a handful of Nissans and Volvos.
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BenB
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| posted on 12/8/08 at 08:43 AM |
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If all lambda sensors are the same why would the controllers and ECUs have calibration graphs? 
A colortune is a reasonable place to start. It'll give you a good idea of what's going on inside the engine.
A wideband lambda gives you a much better idea because you can see what is happening under load etc etc (whereas a colortune is only on zero load)....
but it costs. Then again, a colortune is £20-25 quid whereas a wideband lamda sensor and controller can be had new from triggerwheels.com for about
£120. then you just need a laptop or garage-based desktop to plug it into.....
I went down the colortune route and it was good enough to get me through SVA.
In retrospect I should have bought a wideband.....
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matt_claydon
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| posted on 12/8/08 at 09:51 AM |
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quote:
Originally posted by MikeRJ
Titania based sensors change resistance around the stoichiometric point. These are used on some Vauxhalls, almost all E36 BMWs, many of the Land
Rover/Range Rover V8s, and a handful of Nissans and Volvos.
Fair point. I had heard of this type but thought they were very rare.
There may be minor differences in calibration between brands of sensor, but as far as using one with a multimeter is concerned, they are all the same
and will output either 0v or 1v.
Colortune is not that useful as you can't use it while driving, so you'll only ever be able to tune one edge of a fuel map (or the idle
mixture with carbs).
With a wideband you can still just use it simply with a multimeter as you can calibrate one of the analogue output to read (for example) 0-5v for 10:1
- 20:1 AFR (you need a computer to do the calibration).
A ten quid NB sensor and a multimeter is definitely the cheapest way to start though.
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DarrenW
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| posted on 12/8/08 at 10:24 AM |
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Ive got a narrow band lambda sensor and simple gauge that i dont use any more. Willing to sell. Gauge is a simple box with lights.
Let me know if interested. £25 posted should cover it.
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meany
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| posted on 12/8/08 at 12:56 PM |
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a handy website.
http://www.gendan.co.uk/
[Edited on 12/8/08 by meany]
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sooty
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| posted on 12/8/08 at 05:15 PM |
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Thanks for all your replies.
Been reading some gen on various sites and it seems that the diesel 02 sensor is a wideband.
If this so, could they be used if they have a wideband that everyone mentions??
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