High Lambda... Causes?
Discussion
I had my first "MIL Light" experience yesterday- joy! It comes on from start and stays on nearly all of the time, as it occasionally comes off during overrun and with the throttle fully closed.
"Ok" I think- I shall simply consult the diagnostic software and soon all will be well with the world!
Well, annoyingly, when I run the software, again I'm only able to access the "master screen" and the live graphing screen, so I wasn't able to read the fault code directly. Anyone know why I might not be able to bring up those two screens?
Anyway, it was soon apparent that "Lambda 1" was stuck on 1.8V, and not fluctuating. Lambda 2 seems to be working fine.
Having done a bit of reading, it seems that a lambda stuck at a high value doesn't necessarily mean that its the sensor thats at fault. So, am I right in thinking that this means that the engine is running fully lean, and that there is an air leak somewhere in the system?
Thanks in advance, Rob.
"Ok" I think- I shall simply consult the diagnostic software and soon all will be well with the world!
Well, annoyingly, when I run the software, again I'm only able to access the "master screen" and the live graphing screen, so I wasn't able to read the fault code directly. Anyone know why I might not be able to bring up those two screens?
Anyway, it was soon apparent that "Lambda 1" was stuck on 1.8V, and not fluctuating. Lambda 2 seems to be working fine.
Having done a bit of reading, it seems that a lambda stuck at a high value doesn't necessarily mean that its the sensor thats at fault. So, am I right in thinking that this means that the engine is running fully lean, and that there is an air leak somewhere in the system?
Thanks in advance, Rob.
Well, I've checked for any moisture in the ecu or in the connectors, and having found none, I decided to buy a couple of new lambdas.
The very helpful people at Gendan sold me two branded NTK sensors all in for £130. Only thing I'm worried about now is what caused the lambdas to go off?
The spark plugs are pretty new, so I've popped them into an ultrasonic cleaner for a few hours to bring them back to scratch seeing as the cars been running poorly for a while.
Wish me luck!
P.S I'd still love to know why the diag software wont let me access the fault screen... bloody annoying!
The very helpful people at Gendan sold me two branded NTK sensors all in for £130. Only thing I'm worried about now is what caused the lambdas to go off?
The spark plugs are pretty new, so I've popped them into an ultrasonic cleaner for a few hours to bring them back to scratch seeing as the cars been running poorly for a while.
Wish me luck!
P.S I'd still love to know why the diag software wont let me access the fault screen... bloody annoying!
A high lambda reading in essence means that there is lots of oxygen passing over the sensor - that is the basic way they work.
However, it could be loads of different variables causing the problem. Initially, it may be bad connections between lambdas and ECU (3 pin connector). They may be corroded or loose, or moisture may be affecting the contacts etc. You can take them apart clean them up spray them with electrical connection spray or WD 40 and make sure that the pins are tight in their holders. It may be that the wires from the lambdas are damaged (not had this yet), but you will need to take the lambdas out to be able to check the length of the wires and the joins at each end. It may also be moisture in the main loom wire connecting to the lambdas, or damaged loom connecting wires - if this is the case then doing anything to the lambdas and connections won't make much difference. However, whilst hooked up to the laptop minor movements of the loom (if damaged) may cause false readings on the lambda output.
First off, when connected to the software and up to normal running temp, rev up and down and check that the sensor isn't moving at all. Use F5 to reconnect to ECU if problem occurs and page up and page down to toggle between screens.
A high reading of 1.87 usually means that the engine isn't set up properly or other fault rather than the sensor being at fault.
I have found that the lambdas usually read 0.00 when they are knackered and sometimes raise themselves to 0.01 as a token gesture.
However, if a sensor is stuck on 1.87 then it may mean that it is knackered also - not very helpful I know but this is what I have found.
When you have hooked up to the laptop and are satisfied that the lambda is not moving at all then the next step is to inspect and clean as above. If time is short and you have enough money, then buying new lambdas will solve any problems up to the connection point. Make sure that you give the loom connections (ie ones connectors on end of loom wires) a good clean and spray before connecting the new lambdas and also check for any damage to loom wires. After fitting the new ones (when engine is cold or you'll burn your fingers off) then bring back up to running temperature and see if it's fixed your problem (hook up to laptop etc.). If not repost on this thread and we'll take it from there.
MB
However, it could be loads of different variables causing the problem. Initially, it may be bad connections between lambdas and ECU (3 pin connector). They may be corroded or loose, or moisture may be affecting the contacts etc. You can take them apart clean them up spray them with electrical connection spray or WD 40 and make sure that the pins are tight in their holders. It may be that the wires from the lambdas are damaged (not had this yet), but you will need to take the lambdas out to be able to check the length of the wires and the joins at each end. It may also be moisture in the main loom wire connecting to the lambdas, or damaged loom connecting wires - if this is the case then doing anything to the lambdas and connections won't make much difference. However, whilst hooked up to the laptop minor movements of the loom (if damaged) may cause false readings on the lambda output.
First off, when connected to the software and up to normal running temp, rev up and down and check that the sensor isn't moving at all. Use F5 to reconnect to ECU if problem occurs and page up and page down to toggle between screens.
A high reading of 1.87 usually means that the engine isn't set up properly or other fault rather than the sensor being at fault.
I have found that the lambdas usually read 0.00 when they are knackered and sometimes raise themselves to 0.01 as a token gesture.
However, if a sensor is stuck on 1.87 then it may mean that it is knackered also - not very helpful I know but this is what I have found.
When you have hooked up to the laptop and are satisfied that the lambda is not moving at all then the next step is to inspect and clean as above. If time is short and you have enough money, then buying new lambdas will solve any problems up to the connection point. Make sure that you give the loom connections (ie ones connectors on end of loom wires) a good clean and spray before connecting the new lambdas and also check for any damage to loom wires. After fitting the new ones (when engine is cold or you'll burn your fingers off) then bring back up to running temperature and see if it's fixed your problem (hook up to laptop etc.). If not repost on this thread and we'll take it from there.
MB
Edited by marcus1970 on Wednesday 31st October 09:31
methodwares said:
have you tried the 'page down' key?
I am officialy an idiot. 
Many thanks for your help!I fired on a pair of new lambdas today (£130 for a pair of NTK ones from Gendan), and that along with making sure the throttle pots are set up perfectly had made the world of difference- in fact she's running better than ever!
Today is my also my birthday, and I can hardly think of a better pressie than having my tiv back up to scratch!
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