Discussion
Hi all. I have finally been able to connect the ecu to my laptop! Hurrarhh!! (for anyone else having problems it was the serial to usb converter i was using)
I have had a look at the figures and the trottle % reading only hits about 85% with my foot firmly on the peddle. Surely this should read 100% right? If so whats the remedy?
Also what sort of numbers should i be looking at for the Lambda sensors? I suspect both or one of them is faulty. They are both at 0 at idle and rise with the revs, however one more that the other. Is this right?
Sorry if these are obvious questions.
I have had a look at the figures and the trottle % reading only hits about 85% with my foot firmly on the peddle. Surely this should read 100% right? If so whats the remedy?
Also what sort of numbers should i be looking at for the Lambda sensors? I suspect both or one of them is faulty. They are both at 0 at idle and rise with the revs, however one more that the other. Is this right?
Sorry if these are obvious questions.
Not a good idea to try and use 0 to 100, so often a reduced range is used to ensure the ECU has the actual reading at the correct point. i.e 15% to 85% tells the ECU the closed and fully open position.
This method is used in all phnumatic and electronic controllers throughout the petrochem industry that I have seen.
Steve
This method is used in all phnumatic and electronic controllers throughout the petrochem industry that I have seen.
Steve
GTOBEN said:
okeydoky. So its about right then.
Any ideas on the Lambda sensor readings or what figures they should be showing?
BenAny ideas on the Lambda sensor readings or what figures they should be showing?
I've not got as far as you yet on the Cerb, but I'm sure I read on here that the throttle pots are ranged as you have found.
BUT - we do need an expert to confirm this.
Problem is, as with all similar forums, the regulars get a bit fed up answering the same questions from newbies like me all the time.
So it might be worth searching or looking in the FAQ section for more details.
Steve
. I can confirm from the workshop manual that 15% at closed is correct. No mention of the fully open figure but if both pots are roughly consistent that would seem to mean all is well. I assume they only have 2 as a fall back in case of a failure or maybe the ECU averages. The Emerald only samples one of them I believe from a brief look at the wiring diagram.
There is no such thing as an enrichment map as such. Acceleration enrichment is based on the rate of change of the throttle position.
Narrow band lambda sensors really only show stoichimetric conditions. If it is 0.45v it is 14.7:1 stoich if it is higher it is rich, lower its lean. There is no useful measurement of how rich or how lean with a narrow band sensor, it will read the same at 14:1 as it would at 12:1, just plain rich. They are only used to get a good accurate feel of the stoichimetric point for emmisions purposes at cruise. When you are moving the throttle they are ignored by the ECU to prevent it trying to correct the richened accel mixture back to a lean cruise mixture. They are also ignored during warm up and at or near WOT when the engine would would be destroyed by trying to run a weak cruise mixture.
There is no such thing as an enrichment map as such. Acceleration enrichment is based on the rate of change of the throttle position.
Narrow band lambda sensors really only show stoichimetric conditions. If it is 0.45v it is 14.7:1 stoich if it is higher it is rich, lower its lean. There is no useful measurement of how rich or how lean with a narrow band sensor, it will read the same at 14:1 as it would at 12:1, just plain rich. They are only used to get a good accurate feel of the stoichimetric point for emmisions purposes at cruise. When you are moving the throttle they are ignored by the ECU to prevent it trying to correct the richened accel mixture back to a lean cruise mixture. They are also ignored during warm up and at or near WOT when the engine would would be destroyed by trying to run a weak cruise mixture.
Thanks for the help and insight. My read outs show one hovering around 0.45ish but the other goes to 1.6 which would suggest one is running rich, or i have a faulty lambda? Coughs and splutters alongside a flat spot when you start to accelerate would suggest something is up, or is this the joys of the AJP?
They usually fail showing rich so I would say you have a dud one there. One thing for sure is that what one does the other should do pretty much the same. For what they cost unless you are very sure they are OK I would put a pair of throttle pots on and change the dud lambda sensor. I think from memory the sensors are about £30-£50, the pots about the same for a pair.
fatjon said:
I can confirm from the workshop manual that 15% at closed is correct. No mention of the fully open figure but if both pots are roughly consistent that would seem to mean all is well. I assume they only have 2 as a fall back in case of a failure or maybe the ECU averages. The Emerald only samples one of them I believe from a brief look at the wiring diagram.
There is no such thing as an enrichment map as such. Acceleration enrichment is based on the rate of change of the throttle position.
Narrow band lambda sensors really only show stoichimetric conditions. If it is 0.45v it is 14.7:1 stoich if it is higher it is rich, lower its lean. There is no useful measurement of how rich or how lean with a narrow band sensor, it will read the same at 14:1 as it would at 12:1, just plain rich. They are only used to get a good accurate feel of the stoichimetric point for emmisions purposes at cruise. When you are moving the throttle they are ignored by the ECU to prevent it trying to correct the richened accel mixture back to a lean cruise mixture. They are also ignored during warm up and at or near WOT when the engine would would be destroyed by trying to run a weak cruise mixture.
What percentage throttle does the ECU see as WOT, is it less or greater than 85% There is no such thing as an enrichment map as such. Acceleration enrichment is based on the rate of change of the throttle position.
Narrow band lambda sensors really only show stoichimetric conditions. If it is 0.45v it is 14.7:1 stoich if it is higher it is rich, lower its lean. There is no useful measurement of how rich or how lean with a narrow band sensor, it will read the same at 14:1 as it would at 12:1, just plain rich. They are only used to get a good accurate feel of the stoichimetric point for emmisions purposes at cruise. When you are moving the throttle they are ignored by the ECU to prevent it trying to correct the richened accel mixture back to a lean cruise mixture. They are also ignored during warm up and at or near WOT when the engine would would be destroyed by trying to run a weak cruise mixture.
HarryW said:
fatjon said:
I can confirm from the workshop manual that 15% at closed is correct. No mention of the fully open figure but if both pots are roughly consistent that would seem to mean all is well. I assume they only have 2 as a fall back in case of a failure or maybe the ECU averages. The Emerald only samples one of them I believe from a brief look at the wiring diagram.
There is no such thing as an enrichment map as such. Acceleration enrichment is based on the rate of change of the throttle position.
Narrow band lambda sensors really only show stoichimetric conditions. If it is 0.45v it is 14.7:1 stoich if it is higher it is rich, lower its lean. There is no useful measurement of how rich or how lean with a narrow band sensor, it will read the same at 14:1 as it would at 12:1, just plain rich. They are only used to get a good accurate feel of the stoichimetric point for emmisions purposes at cruise. When you are moving the throttle they are ignored by the ECU to prevent it trying to correct the richened accel mixture back to a lean cruise mixture. They are also ignored during warm up and at or near WOT when the engine would would be destroyed by trying to run a weak cruise mixture.
What percentage throttle does the ECU see as WOT, is it less or greater than 85% There is no such thing as an enrichment map as such. Acceleration enrichment is based on the rate of change of the throttle position.
Narrow band lambda sensors really only show stoichimetric conditions. If it is 0.45v it is 14.7:1 stoich if it is higher it is rich, lower its lean. There is no useful measurement of how rich or how lean with a narrow band sensor, it will read the same at 14:1 as it would at 12:1, just plain rich. They are only used to get a good accurate feel of the stoichimetric point for emmisions purposes at cruise. When you are moving the throttle they are ignored by the ECU to prevent it trying to correct the richened accel mixture back to a lean cruise mixture. They are also ignored during warm up and at or near WOT when the engine would would be destroyed by trying to run a weak cruise mixture.
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