Running rich, but only some of the time?
Discussion
[ Vehicle: 2002 4.4 V8 Range Rover + Sequential LPG ]
Recently began to get some stuttering on acceleration. I ran the diagnostic and was told that the MAF sensor was to low a value. On a run I could see that the MAF reading remained constant. So I went and replaced the MAF ( with an aftermarket one, but not the cheapest I could find ) and reset all the adaptation values.
Putting the MAF back on, and now I get MAF readings which match the throttle response:
( At idle I get a reading of about 38 kg/hr ? - is that high for a 4.4 na engine )
However, now I'm getting error codes showing both banks running too rich. On the same run as above, theses are the lambda readings from both banks....
Both banks are giving almost exactly same readings ( I assume thats good ) ... and on medium throttle, the values seem to bounce around the 1 mark ( ish ). On the 2 kick downs, the lambda is bang on 1 - which is what you want.
So does anyone have any idea why the lambda drops down to 0.74 the rest of the time? I was under the impression that even at idle, the lambda would be bouncing above and below the 1 mark.
As I understand it: RICH < 1 < LEAN so the 0.74 means its running rich.
Can anyone offer any suggestions?
Is it possible that I've not given enough time to allow the adapation value to reset?
Any thoughts / ideas are gratefully appreciated.
Don Fisher
Recently began to get some stuttering on acceleration. I ran the diagnostic and was told that the MAF sensor was to low a value. On a run I could see that the MAF reading remained constant. So I went and replaced the MAF ( with an aftermarket one, but not the cheapest I could find ) and reset all the adaptation values.
Putting the MAF back on, and now I get MAF readings which match the throttle response:
( At idle I get a reading of about 38 kg/hr ? - is that high for a 4.4 na engine )
However, now I'm getting error codes showing both banks running too rich. On the same run as above, theses are the lambda readings from both banks....
Both banks are giving almost exactly same readings ( I assume thats good ) ... and on medium throttle, the values seem to bounce around the 1 mark ( ish ). On the 2 kick downs, the lambda is bang on 1 - which is what you want.
So does anyone have any idea why the lambda drops down to 0.74 the rest of the time? I was under the impression that even at idle, the lambda would be bouncing above and below the 1 mark.
As I understand it: RICH < 1 < LEAN so the 0.74 means its running rich.
Can anyone offer any suggestions?
Is it possible that I've not given enough time to allow the adapation value to reset?
Any thoughts / ideas are gratefully appreciated.
Don Fisher
As the AFM is the major component to meter the fueling, and you dont have an OEM one, id suspect about the calibration. Some of the Chinese replicas are truely horrible, and only work at all on system that run closed loop all the time and can correct for the poor voltages. I assume you have a Lucas Sagem system ?
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