luke85
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Registered: 26th Nov 07
Location: Chesterfield
User status: Offline
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You have to test it with the lambda connected, no point doing it without it plugged in. you can get the test lead down the side of the wires with the connectors together
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jord77
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Registered: 12th Mar 04
Location: Winterley, Cheshire
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arrr right sorry will go try it now back in a sec
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luke85
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Registered: 26th Nov 07
Location: Chesterfield
User status: Offline
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I tested mine the other day but i cant remember which wire it is but on a narrowband its a 0-1V signal.
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jord77
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Registered: 12th Mar 04
Location: Winterley, Cheshire
User status: Offline
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if u sat the plug flat on a desk the right way up there are 2 white wires on the left and the black on the right how did u test yours ??? how have u got it connected u got any pics
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luke85
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Registered: 26th Nov 07
Location: Chesterfield
User status: Offline
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you have to have it in the car connected as normal. then put the meter negative to the battery negative to leave you 2 hands free. start the car and squeeze the + into the connector if its thin enough, or you could hold the wire and poke the end of the probe through the insulation, it will only give you a pin hole which will close when you take the lead away again. have you connected your gauge to what you believe to be the signal wire? if you have it will be easier to test it from the back of your gauge
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luke85
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Registered: 26th Nov 07
Location: Chesterfield
User status: Offline
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Just for anyone who is curious, this is what the signal from a narrowband sensor looks like at different air/fuel ratios:
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0.45Volts is lambda = 1 which is the mixture where all the fuel is burned with no oxygen left over
The problem is that it can only read between 0.958 lambda (1.1V) and 1.022 lambda (0.103V)
This translates to reading an air fuel ratio of between 14.08 : 1 and 15.02 :1
both of these are way too lean for a turbo engine which needs to be 11 or 12 to one. so even if your gauge reads rich, it may still be way too lean if you are on boost, thats why the ECU ignores the lambda sensor at full throttle and only uses it to keep the mixture correct at cruising speeds where a turbo car can quite happily sit at 14.7:1
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jord77
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Registered: 12th Mar 04
Location: Winterley, Cheshire
User status: Offline
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just tested it and its geting 0.4 volts ?? on the signal wire
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jord77
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Registered: 12th Mar 04
Location: Winterley, Cheshire
User status: Offline
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as well connected the gauge stright to the bat as well and its just sat on rich on the gauge, rev the car it dont move
[Edited on 18-12-2007 by jord77]
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jord77
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Registered: 12th Mar 04
Location: Winterley, Cheshire
User status: Offline
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just connected the mutimeter with the plug conected and its reading 0.4 volts changed the landa sesor yesterday and no joy taken the gauge out of car now and connected it to the bat and conected the grey wire to the signal wire and still nothing
[Edited on 18-12-2007 by jord77]
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Dave A
USER UNDER INVESTIGATION - DO NOT TRADE
Registered: 10th Dec 03
Location: County Durham
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get a proper gauge that uses its own wideband sensor, you will never get anything usefull from the one you are using.
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luke85
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Registered: 26th Nov 07
Location: Chesterfield
User status: Offline
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0.4V is what it should be reading on idle, on full throttle with boost it should go richer. Have you got an old lambda sensor you dont want? Ive been looking for one that i can rob the connector from
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