Lambda sensors dead?
Discussion
Good morning,
On my 4.5 Cerb both lambdas were stuck on 0.00v . I figured this was due to them both dying, as apparently they do. So I ordered 2 new ones.
Installed last night and they both read 0.00v. Checking over this morning with a temperature gun and when cold I'm getting 13 deg C. With ignition on I get up to 27 deg on the RH sensor and 15 deg on the LH sensor. This is measured at the nut where it bolts into the exhaust. With the engine off and the ignition on I am getting readings (0.1 ish) yet as soon as I start the car they both go to zero and the adaptives start doing their thing.
I've read about issues with voltage at the heating element, is this something people have solved? I'm flat out finding the things on the wiring diagrams.
Has anybody else had this issue?
On my 4.5 Cerb both lambdas were stuck on 0.00v . I figured this was due to them both dying, as apparently they do. So I ordered 2 new ones.
Installed last night and they both read 0.00v. Checking over this morning with a temperature gun and when cold I'm getting 13 deg C. With ignition on I get up to 27 deg on the RH sensor and 15 deg on the LH sensor. This is measured at the nut where it bolts into the exhaust. With the engine off and the ignition on I am getting readings (0.1 ish) yet as soon as I start the car they both go to zero and the adaptives start doing their thing.
I've read about issues with voltage at the heating element, is this something people have solved? I'm flat out finding the things on the wiring diagrams.
Has anybody else had this issue?
The lambdas have 11.8v at the plug, with no fuel pump running. I haven't checked for continuity to the ECU yet.
The fuses are all good!
Imran, what TPS setting at idle did you end up with? I'm currently at around 14.5%. I did briefly try around 18% whilst idling with no luck. Maybe I need to try a higher TPS and actually drive it till it's hot.
The fuses are all good!
Imran, what TPS setting at idle did you end up with? I'm currently at around 14.5%. I did briefly try around 18% whilst idling with no luck. Maybe I need to try a higher TPS and actually drive it till it's hot.
Edited by mrniceguy351 on Friday 13th May 19:45
DuncanM said:
If the car is running nicely, you could post a link of some logs? You'd get a lot more accurate feedback from that, than from a screenshot of idle. The logging is pretty simple to start on rs-ajp.
I haven't worked out how to do that yet, but the car basically tips in more fuel whenever it spends time in part of the table that it hasn't already maxed out the adaptives for. The lambdas are stuck at 0% at all rpm and throttle ranges with idle TPS set at anywhere from 12% to 20+% spitfire4v8 said:
You need to take some steps back
from your screenshot you already have a high TP values so you should already be running in a richer part of the mapping, yet you still have high adaptives and no lambda output. Those things should not exist together. There are several reasons why this might be the case, but you need to go back to basics and start checking some fundamental values.
So ..
Do you have an airflow measuring device? If so what is the airflow through the butterflies?
Idling smoothly at 970 rpm, with the adaptives reset.from your screenshot you already have a high TP values so you should already be running in a richer part of the mapping, yet you still have high adaptives and no lambda output. Those things should not exist together. There are several reasons why this might be the case, but you need to go back to basics and start checking some fundamental values.
So ..
Do you have an airflow measuring device? If so what is the airflow through the butterflies?
spitfire4v8 said:
Right, so you have lowish airflows and high throttle sensors so it definitely should be running rich not weak, all other things being equal.
So .. when you reset the adaptives does the engine revs fall, and then pick up as the ecu adds fuel ? Or does it barely make any difference ? or does it speed up and then start to lose revs as the adaptives increase?
It sped up when I reset the adaptives, 50-76 rpm.So .. when you reset the adaptives does the engine revs fall, and then pick up as the ecu adds fuel ? Or does it barely make any difference ? or does it speed up and then start to lose revs as the adaptives increase?
So I did this...
With the car running if I throw -12v to the earth for the lambda I get a reading. A very low reading (0.1) but still a reading. This is with the exhaust dropped btw, and the lambda sensor is only 50mm from the open exhaust pipe.
Tomorrows mission is to unplug the other sensor,pull that part of the loom into the engine bay, strip the insulation off and look at running a new common earth and maybe power wire to the sensors.
Strangely enough when I probed the red wire that also showed as an earth, I guess because it's earthed via the lambda? It also struck me that the wires to the sensors are tiny!
With the car running if I throw -12v to the earth for the lambda I get a reading. A very low reading (0.1) but still a reading. This is with the exhaust dropped btw, and the lambda sensor is only 50mm from the open exhaust pipe.
Tomorrows mission is to unplug the other sensor,pull that part of the loom into the engine bay, strip the insulation off and look at running a new common earth and maybe power wire to the sensors.
Strangely enough when I probed the red wire that also showed as an earth, I guess because it's earthed via the lambda? It also struck me that the wires to the sensors are tiny!
Who is the man? Me, that's who. The best Cerbera troubleshooter in all of Western Australia!
Fed 12v direct from the battery to the lambdas, and made a new earth to the back of the motor and they both came to life. But they were only reading 0.01v, so I connected the exhaust up and bingo, getting good readings from both. (The screenshot doesn't show it but I did have good readings from the RHS lambda as well.)
Now I just need to decide where to connect the new 12v feed. I have electric power steering so I was thinking of running it from there. A bit of a round about way to do it, but the wiring is all new and oversize. I will need a diode and it's a public holiday today so that will have to wait till tomorrow.
Fed 12v direct from the battery to the lambdas, and made a new earth to the back of the motor and they both came to life. But they were only reading 0.01v, so I connected the exhaust up and bingo, getting good readings from both. (The screenshot doesn't show it but I did have good readings from the RHS lambda as well.)
Now I just need to decide where to connect the new 12v feed. I have electric power steering so I was thinking of running it from there. A bit of a round about way to do it, but the wiring is all new and oversize. I will need a diode and it's a public holiday today so that will have to wait till tomorrow.
glow worm said:
I had lots of trouble last year with "cheap" Lambdas on my Chimaera... caused by poor wiring to the Lambdas not being able to withstand the heat generated are you sure your solution will work in the extreme heat ?
It will work a lot better than the original tiny wires, and will be routed well away from the exhaust.I have a new radiator and fans, I don't really have "extreme" heat under the bonnet.
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