P38A MAF etc opinions

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oakey

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Mull of Kintyre
Hiya
V8 95 auto 186k
Has got newish plugs and a SS exhaust last MOT and new exhaust is twin pipe whilst original was single pipe.
Adaptive values are something like 127% and 3 or 4% on other bank. I dont really understand what an adaptive value is but presume it is a number that relates to injector opening time and is determined by O2 sensor.
She just passed her MOT and was thinking of rewarding her by cleaning MAF.
Good idea?
Ta much
 
Yes i can understand that view but I have no idea if it is broke or not. MPG isnt as good as it used to be but engine goes fine

The readings were from Nanocom
 
There is ‘special’ MAF cleaner you can buy. Not sure what it is though or how good, could be watered down snake oil for all I know, I have no MAF on purpose - horrid things and pricey

MAF on a diesel is there for a total different reason than a MAF on a petrol engine.
 
Makes sense now - air is constant in doozles cylinder.

Are there different cleaners? I’m sure redex used to be different types carb/diesel, turbo/non just fuel type now.

Just so, MAF is for exhaust gas measurement when EGR is active. The reduction in airflow indicates exhaust gas ingestion. Redex would never go near the MAF sensor. So not an issue, may have been different formula for diesel/petrol. When i took over the garage business i used to own, i inherited a half full 45 gallon drum of Redex.
 
The can of stuff I have says petrol MAF cleaner.
Nanocom doesnt say that Lambda sensors are knackered but adaptive values are totally different between banks and I have no idea what a "good" adaptive value is
 
The adaptive values are a number of things that the ECU learns while the car is being driven, so things like correction factors on the MAF sensor, long term fuel trims etc etc.
The adaptives are things like a MAF correction factor, a correction to the fuel mapping to account for worn injectors, a iffy/old fuel pressure regulator etc etc , on a brand new engine with brand new sensors and everything working as it should, then there will be no corrections needed so the factory settings in the engine ECU will be spot on. But, you don't have brand new components so things will have aged and that is where the adaptive values come into play, best reset them and take her for a run, varying throttle and load situations..

Kick down a few times etc etc.

On a Gems P38 the adaptive values are lost when a bettery is disconnected, so they'll have to be "reprogrammed" in with a good drive..
 
Thats great Henryb very useful thank you
I have just changed all the filters apart from fuel which is tomorrow but I wont change values unti just before I am going on a long run.
Thank you
 
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