Speed Six high lambda readings 1.85v
Discussion
I'm nearing the end of my Tuscan restoration and finally got the laptop connected to the MBE ECU as I've been getting the 'EFi fault' on the dash when staring her up. It's definitely running rich but other than that sounds good but the Lambda readings are very high, both showing identical 1.85v at idle, see pic below. Bare in mind the car hasn't been driven in over 2 years...
I have done the Lambda wiring mod so the first thing I'll be triple checking is my wiring. If the wiring is ok, which I’m fairly confident it is, what else could be causing these readings? I'd be surprised if both Lambdas are duff but anything is possible, maybe need cleaning?
Any help would be gratefully received
I have done the Lambda wiring mod so the first thing I'll be triple checking is my wiring. If the wiring is ok, which I’m fairly confident it is, what else could be causing these readings? I'd be surprised if both Lambdas are duff but anything is possible, maybe need cleaning?
Any help would be gratefully received
Hi, Not sure of the mod you talk about, however - from the original RTHelp.txt file (might help): -
LAMBDA 1 & LAMBDA 2
Lambda 1&2 show the signals from the lambda sensors on each bank. After starting the
sensors will take at least 30 seconds to warm up, before they will read correctly .
Once warmed up, the lambda signals should switch between approx. 0 & 1-1.5 volts.
0 volts shows that the fuel mixture is lean, 1 volt shows that the mixture is rich.
The rate of switching will alter with engine speed, and the percentage of time spent
rich relative to lean will alter with engine load. If reading is a CONSTANT 0 V, check
sensor for proper connection, and sensor heater wires for continuity (6 ohms between
white red wires)
NOTE: Lambda sensors are supplied with 12V on the red wires ONLY WHEN THE
FUELPUMP IS RUNNING, the WHITE wire is earth and BLACK the signal.
LAMBDA 1 & LAMBDA 2
These faults are shown if the lambda sensor signal rises above 1.7V.If it occurs the
MIL lamp will be turned on.
Lambda fault
can be caused by: Water ingress into the lambda sensor's connector or wiring.
Mechanical damage to sensor or wiring, causing a short
between the supply and signal wires.
Faulty sensor
I would look at your wiring mod first.
LAMBDA 1 & LAMBDA 2
Lambda 1&2 show the signals from the lambda sensors on each bank. After starting the
sensors will take at least 30 seconds to warm up, before they will read correctly .
Once warmed up, the lambda signals should switch between approx. 0 & 1-1.5 volts.
0 volts shows that the fuel mixture is lean, 1 volt shows that the mixture is rich.
The rate of switching will alter with engine speed, and the percentage of time spent
rich relative to lean will alter with engine load. If reading is a CONSTANT 0 V, check
sensor for proper connection, and sensor heater wires for continuity (6 ohms between
white red wires)
NOTE: Lambda sensors are supplied with 12V on the red wires ONLY WHEN THE
FUELPUMP IS RUNNING, the WHITE wire is earth and BLACK the signal.
LAMBDA 1 & LAMBDA 2
These faults are shown if the lambda sensor signal rises above 1.7V.If it occurs the
MIL lamp will be turned on.
Lambda fault
can be caused by: Water ingress into the lambda sensor's connector or wiring.
Mechanical damage to sensor or wiring, causing a short
between the supply and signal wires.
Faulty sensor
I would look at your wiring mod first.
notaping, that's spot-on.
I unplugged one sensor and tested for continuity across the red and white wires (old 3 wire sensor) and there was a short, checked the corresponding connector to the loom, no short, did the same on the other sensor and that sensor's shorted also so both sensors look like they're goosed.
So, this applies from your list notaping, thank you:
'LAMBDA 1 & LAMBDA 2
These faults are shown if the lambda sensor signal rises above 1.7V. If it occurs the
MIL lamp will be turned on.
Lambda fault
can be caused by: Water ingress into the lambda sensor's connector or wiring.
Mechanical damage to sensor or wiring, causing a short
between the supply and signal wires.
Faulty sensor'
So, the next question is where do I get the correct lambdas from (with the correct thread for early MK1s, M12x1.25?) and do I change to the easier to find 4 wire sensors?
A quick search brings up these:
https://www.ebay.co.uk/itm/113007862849
LAND ROVER DISCOVERY MK1 2.0 MPI (1993-97) 4 WIRE FRONT LAMBDA OXYGEN SENSOR
And a quick google states these are m12x1.25 thread which I think is correct, can someone confirm?
So, it looks like these are the correct ones for my Tuscan.
The conversion from 3 to 4 wire seems easy, it's just an additional earth, is this correct?
pinouts copied from another thread:
1) Black wire on TVR loom (grey wire on sensor) = additional earth for lambda signal
2) Black wire on TVR loom (white wire on sensor) = lambda heater earth
3) Red wire on TVR loom (other white wire on sensor) = lambda heater
4) Yellow wire on TVR loom (black wire on sensor) = lambda signal
I unplugged one sensor and tested for continuity across the red and white wires (old 3 wire sensor) and there was a short, checked the corresponding connector to the loom, no short, did the same on the other sensor and that sensor's shorted also so both sensors look like they're goosed.
So, this applies from your list notaping, thank you:
'LAMBDA 1 & LAMBDA 2
These faults are shown if the lambda sensor signal rises above 1.7V. If it occurs the
MIL lamp will be turned on.
Lambda fault
can be caused by: Water ingress into the lambda sensor's connector or wiring.
Mechanical damage to sensor or wiring, causing a short
between the supply and signal wires.
Faulty sensor'
So, the next question is where do I get the correct lambdas from (with the correct thread for early MK1s, M12x1.25?) and do I change to the easier to find 4 wire sensors?
A quick search brings up these:
https://www.ebay.co.uk/itm/113007862849
LAND ROVER DISCOVERY MK1 2.0 MPI (1993-97) 4 WIRE FRONT LAMBDA OXYGEN SENSOR
And a quick google states these are m12x1.25 thread which I think is correct, can someone confirm?
So, it looks like these are the correct ones for my Tuscan.
The conversion from 3 to 4 wire seems easy, it's just an additional earth, is this correct?
pinouts copied from another thread:
1) Black wire on TVR loom (grey wire on sensor) = additional earth for lambda signal
2) Black wire on TVR loom (white wire on sensor) = lambda heater earth
3) Red wire on TVR loom (other white wire on sensor) = lambda heater
4) Yellow wire on TVR loom (black wire on sensor) = lambda signal
Modrich. Shame it wasn't the wiring - a much cheaper fix.
I'm afraid I can't advise on which ones to get. The last ones I got were NGK OTD3G-3A1 Lambda Sensor with the white round connectors, like these. . .
https://www.ebay.co.uk/itm/235475759881?mkcid=16&a...
but they were for a Cerb V8. Don't know if they're the same on a Tuscan. Sorry.
I'm afraid I can't advise on which ones to get. The last ones I got were NGK OTD3G-3A1 Lambda Sensor with the white round connectors, like these. . .
https://www.ebay.co.uk/itm/235475759881?mkcid=16&a...
but they were for a Cerb V8. Don't know if they're the same on a Tuscan. Sorry.
That's great notaping, that's given me somewhere to start looking. So I've done some cross referencing using the NGK catalogue.
If you have an early MK1 Tuscan like mine with 3 wire sensors then this looks like the Lambda sensor you need:
NGK part no. OTD3G-3A1 from £70ea
stock no. 0453
No. of wires 3
Connector Type 55 (white round)
Cable length 521mm
Thread M12x1.25
TVR CERBERA 4.2 V8 96-04
TVR CHIMERA 4.0 V8 93-00
TVR GRIFITH 4.0 V8 90-93
LAND ROVER DEFENDER 3.5 88 to 98
LAND ROVER DISCOVERY Mk1 3.5 3.9 88 to 98
LAND ROVER RANGE ROVER 3.5 3.9 4.2 88 to 94
ROVER 800 2.0I 88 - 91
If you want the cheaper option and don't mind converting to 4 wire:
NGK part no. OTD3J-5C1 from £21ea
stock no. 0475
No. of wires 4
Connector Type 43 (GREY)
Cable length 521mm
Thread M12x1.25
LAND ROVER DEFENDER 4.0 88 to 98
Land Rover Range Rover II 4.6 4.0 97-98 Front sensor
I'll be ordering the 4 wire...
If you have an early MK1 Tuscan like mine with 3 wire sensors then this looks like the Lambda sensor you need:
NGK part no. OTD3G-3A1 from £70ea
stock no. 0453
No. of wires 3
Connector Type 55 (white round)
Cable length 521mm
Thread M12x1.25
TVR CERBERA 4.2 V8 96-04
TVR CHIMERA 4.0 V8 93-00
TVR GRIFITH 4.0 V8 90-93
LAND ROVER DEFENDER 3.5 88 to 98
LAND ROVER DISCOVERY Mk1 3.5 3.9 88 to 98
LAND ROVER RANGE ROVER 3.5 3.9 4.2 88 to 94
ROVER 800 2.0I 88 - 91
If you want the cheaper option and don't mind converting to 4 wire:
NGK part no. OTD3J-5C1 from £21ea
stock no. 0475
No. of wires 4
Connector Type 43 (GREY)
Cable length 521mm
Thread M12x1.25
LAND ROVER DEFENDER 4.0 88 to 98
Land Rover Range Rover II 4.6 4.0 97-98 Front sensor
I'll be ordering the 4 wire...
Hhmm.
I wonder if I can fit those 4-wire ones to my Tam (3.6) as the spare manifolds I got ceramic coated were M12 size lambda sensor bosses.
I assume you wire three of the wires into the loom and then the fourth off to an earth on the block (thus doing the wiring mod on the four wire set up).
I wonder if I can fit those 4-wire ones to my Tam (3.6) as the spare manifolds I got ceramic coated were M12 size lambda sensor bosses.
I assume you wire three of the wires into the loom and then the fourth off to an earth on the block (thus doing the wiring mod on the four wire set up).
mk1fan said:
Hhmm.
I wonder if I can fit those 4-wire ones to my Tam (3.6) as the spare manifolds I got ceramic coated were M12 size lambda sensor bosses.
I assume you wire three of the wires into the loom and then the fourth off to an earth on the block (thus doing the wiring mod on the four wire set up).
I thought the later 4 wire sensors were zirconia, not titania from the wire colours?I wonder if I can fit those 4-wire ones to my Tam (3.6) as the spare manifolds I got ceramic coated were M12 size lambda sensor bosses.
I assume you wire three of the wires into the loom and then the fourth off to an earth on the block (thus doing the wiring mod on the four wire set up).
According to NTK catalogue they're both Titania so the 4 wire should be ok for early MK1 Tuscan. Mk1fan I think you're right, just earth the 4th wire as the Lambda wiring mod.
I have a confession to make, my lambdas are ok, as notaping suggested, it was my wiring mod that was the problem. I had got the black and white wires on the 3 wire lambda swapped. I've done so much wiring on the Tuscan that my brain told me the black wire was the earth and signal wire was white but it's the other way round. I swapped the pins on the new plugs I fitted and now the lambda voltages are as they should be.
I have a confession to make, my lambdas are ok, as notaping suggested, it was my wiring mod that was the problem. I had got the black and white wires on the 3 wire lambda swapped. I've done so much wiring on the Tuscan that my brain told me the black wire was the earth and signal wire was white but it's the other way round. I swapped the pins on the new plugs I fitted and now the lambda voltages are as they should be.
Yeah, they arrived today, wrong size M18. The plot thickens. I need to message the seller and see what they say. If you use the Land Rover part number AMR6244 on eBay then the correct ones come up at about £50. The way to check is from the picture the thread should be just a mil or 2 larger than the sensor end.
These are the correct 4 wire M12 lambdas, so they do exist...
https://www.ebay.co.uk/itm/296196568124?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=MCVvYV1dS9-&sssrc=4429486&ssuid=ZO1xRH8QSnu&var=&widget_ver=artemis&media=COPY
https://www.ebay.co.uk/itm/296196568124?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=MCVvYV1dS9-&sssrc=4429486&ssuid=ZO1xRH8QSnu&var=&widget_ver=artemis&media=COPY
I think I got that link to work - initially gave a 404 message - and they look like 3-wire versions. Thanks though.
I found these on Rimmer Bros but it isn't clear if they are 4-wire, M12 or Titania. I emailed the sales dept and they can't answer the query, they just use car reg / chassis number to match parts.
I may take a punt on one of the cheap ones - I only need one at the moment.
https://rimmerbros.com/Item--i-AMR6244P
https://rimmerbros.com/Item--i-MHK100930P
I found these on Rimmer Bros but it isn't clear if they are 4-wire, M12 or Titania. I emailed the sales dept and they can't answer the query, they just use car reg / chassis number to match parts.
I may take a punt on one of the cheap ones - I only need one at the moment.
https://rimmerbros.com/Item--i-AMR6244P
https://rimmerbros.com/Item--i-MHK100930P
Quick follow up on this.
I ordered one of these - https://rimmerbros.com/Item--i-MHK100930P - and it is an M18 4-wire item. I may try it in the car to see if it is suitable.
This is the other one I linked too - https://rimmerbros.com/Item--i-AMR6244P - which is a 4-wire item but I can't tell if it is an M12 or M18 version.
I found these genuine items - https://rimmerbros.com/Item--i-ERR1834 - which again are 4-wire and look like M12 but I don't fancy spending £300 to find out (and Rimmer don't know they only cross reference vin numbers.
I found this which appears to be an aftermarket OEN item - https://rimmerbros.com/Item--i-ERR1834P1 - but with a black plug.
I am going to order an AMR6244P and a ERR1834P1 and try them.
I ordered one of these - https://rimmerbros.com/Item--i-MHK100930P - and it is an M18 4-wire item. I may try it in the car to see if it is suitable.
This is the other one I linked too - https://rimmerbros.com/Item--i-AMR6244P - which is a 4-wire item but I can't tell if it is an M12 or M18 version.
I found these genuine items - https://rimmerbros.com/Item--i-ERR1834 - which again are 4-wire and look like M12 but I don't fancy spending £300 to find out (and Rimmer don't know they only cross reference vin numbers.
I found this which appears to be an aftermarket OEN item - https://rimmerbros.com/Item--i-ERR1834P1 - but with a black plug.
I am going to order an AMR6244P and a ERR1834P1 and try them.
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