New Lambda gone bad after drive home
Discussion
I had my Lambda sensors changed (both were knackered) during a service recently in Blackpool. Everything was good, car running sweet. I Started the car today and got the MIL light. I plugged in the laptop and ive got a Lambda 2 fault, constant reading of 1.8.
Dont know how it can have gone from good to bad overnight. When they failed before they read 0v and didnt switch, I havent seen a constant of 1.8 volts before.
Any Ideas????
Dont know how it can have gone from good to bad overnight. When they failed before they read 0v and didnt switch, I havent seen a constant of 1.8 volts before.
Any Ideas????
Mine failed recently after getting a soaking from a power hose - showed the same symptons (contsant 1.8V).
My understand of how the three wire system works (and this might help explain your fault), is that there's a high-current heater circuit on two of the wires and a low current sensor circuit on the remaining one (using the same earth as the heater circuit?). If you get a short between the high-current circuit and the low current circuit, it burns out the sensor.
I'd advise checking thoroughly up and down the wire to the lambda (including in the little white connector under the scuttle). I've seen the wires contact the exhaust manifold and get fused together to cause a short, or you may have moisture in the connector.
I should underline though that this is only my understanding, so don't take it as gospel.
My understand of how the three wire system works (and this might help explain your fault), is that there's a high-current heater circuit on two of the wires and a low current sensor circuit on the remaining one (using the same earth as the heater circuit?). If you get a short between the high-current circuit and the low current circuit, it burns out the sensor.
I'd advise checking thoroughly up and down the wire to the lambda (including in the little white connector under the scuttle). I've seen the wires contact the exhaust manifold and get fused together to cause a short, or you may have moisture in the connector.
I should underline though that this is only my understanding, so don't take it as gospel.
The lambdas themselves are a bit of a swine to get to. Even worse, the two cables for left and right lambda are usually cable-tied together over the top of the gearbox.
That said, physically looking at the lambda will tell you precisely f
k all, so unless you've going all the way and changing it yourself, you might as well get whoever's fitting it for you to do the checking on your behalf.
What might be more fruitful is to have a good look at the connector plugs under the scuttle. If you pull the F1 panel off and stand on the drivers side, you'll see a set of thin-gauge disappearing into the cavity your side of the starter motor assembly. Follow those down, and you'll find a pair of white connectors (I would call them bullets, but they're the pinch'n'pull type). Pull them apart and check they're not full of water or otherwise damaged.
TBH, if you've replaced a lambda and its blown immediately, the problem is going to be on the ECU side of that connector.
Oh, and while I'm writing, don't pay £120 or whatever TVR power charge. The lambdas are 3.9 V8 Land rover items, and Island4x4 sell them for £54. If you order a £1.25 oil filter too, they'll even scrap the £5 postage. Don't get confused with the more expensive "modded" lambdas which are only available from TVR sources - these are for Speed 6 engines.
That said, physically looking at the lambda will tell you precisely f
k all, so unless you've going all the way and changing it yourself, you might as well get whoever's fitting it for you to do the checking on your behalf.What might be more fruitful is to have a good look at the connector plugs under the scuttle. If you pull the F1 panel off and stand on the drivers side, you'll see a set of thin-gauge disappearing into the cavity your side of the starter motor assembly. Follow those down, and you'll find a pair of white connectors (I would call them bullets, but they're the pinch'n'pull type). Pull them apart and check they're not full of water or otherwise damaged.
TBH, if you've replaced a lambda and its blown immediately, the problem is going to be on the ECU side of that connector.
Oh, and while I'm writing, don't pay £120 or whatever TVR power charge. The lambdas are 3.9 V8 Land rover items, and Island4x4 sell them for £54. If you order a £1.25 oil filter too, they'll even scrap the £5 postage. Don't get confused with the more expensive "modded" lambdas which are only available from TVR sources - these are for Speed 6 engines.
well its defo the sensor. i have inspected the plugs asnd switched them round to see if the fault transfered to the other bank, which it did. this is a speed six engine by the way and its lambda 2 on bank 456. Greenstar changed the old one but as they are in blackpool and im in glasdgow it looks like im going to have to try to get this one out myself. being under the exhasust manifold and wedged behind the chasis it looks like a piece of cake....NOT
Any one pulled one out before?
Any one pulled one out before?
WELL........an interesting day
turns out the lambdas were connected back to front. That would explain the AFR faults on both banks I have had since picking the car up and the strange lambda readings, not to mention the lumpy take off from stand still. I connected them in the right order and all looked ok. Both lambdas switching. Went a test drive and now Lambda 2 (which is lambda 2 now and not actually 1) is intermittantly spiking above 1.7 volts setting the MIL alarm off. The AFR faults are clear which is good but im now wondering if the lambda sensor has been damaged when connected to the wrong set of cylinders
turns out the lambdas were connected back to front. That would explain the AFR faults on both banks I have had since picking the car up and the strange lambda readings, not to mention the lumpy take off from stand still. I connected them in the right order and all looked ok. Both lambdas switching. Went a test drive and now Lambda 2 (which is lambda 2 now and not actually 1) is intermittantly spiking above 1.7 volts setting the MIL alarm off. The AFR faults are clear which is good but im now wondering if the lambda sensor has been damaged when connected to the wrong set of cylinders
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