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Discussion Starter #1
Had a fault showing up recently on the v6 showing the lambda was at fault and basically she holds back in places but mainly around 4000rpm....
So i tried 2 spares (already used) i had here and the fault remained.I went and bought a new lambda (ngk) friday and fitted it and low and behold the fault is still there :mad:
So i took out the superchipped ecu and replaced it with the spare oe 1 only to find the problem still exist.Ive also checked and exchanged the afm just in case but still to no avail.Ive also been through and checked the wiring connections etc and they dont show any fault and are clean etc.
Yes i have cleared the fault code each time ive swapped components.

Now what ive done today is put a voltmeter on the return from the lambda's (old and new) to the ecu which actually shows the voltage to be consistently flickering from 0.2volts to 0.7volts on tickover.
Now as far as im aware the reading should be in the 0.6-0.9volt region but because it dips right down to 0.2 its giving me the fault code. (my assumption but is it correct)
The variation on volts looks consistent with a pulse but i dont reckon this is correct and dont believe it should do this :confused: .The main feed into the lambda is a consistent 13.8volts.

Job tomorrow i guess is to try and ensure that its firing correctly on all 6 cylinders and its not missfiring but i cant say its apparent :confused:
So anyone got any wise ideas?
 

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Hi Martin,
Russ bought a cheap AFR meter off Observer when we were having lambda probs, £20 IIRC. Makes diagnosis very simple and can be used easily on other peoples cars so will quickly pay for itself.
0.2 to 0.7 sounds about right on tickover. We wired the AFR in permanantly to both lambdas in the end via a switch, lets u compare both engine banks.
 

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Discussion Starter #3
Thing is Paul thre is only 1 lambda sensor on the cav/cally v6 engine so in effect says it should be slightly easier to rectify although its not proved so simple.......
Ive got a dynotune a/f ratio meter which is where i have picked up the fluctuation problem in voltage.(ive also checked it via voltmeter) Im sure the problem lies in the fact the voltage is "pulsing" from no voltage - 0.2volts - 0.7 volts reoccuring every few seconds over and over again.
 

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All the lambdas we have constantly track up and down from red into the green on tickover (after they have warmed up that is), it sounds like its doing its job TBH. Its when they stay in one spot or become lazy, reacting slowly that causes problems.
 
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