Fuel trim groups 032 033 Audi A6C6 fuel mixture poor or rich
What values should be in groups 032 and 033 (for example, #Audi #A6C6 2.4 BDW):
In the 032 group, the additive and multiplicative are normal -10%..+10%, good values -5%..+5%, if more than -20%..+20% - this is TROUBLE
In the 033 group, you need to wait until the values are -1%..+1% and will constantly go from negative values to positive and so on, this means that the fuel mixture has adapted and you can view the values in the 032 group
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Additive - 1 and 3 window in 032 group-adaptation at idle
Multiplicative - 2 and 4 window in 032 group-adaptation under load in motion
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Negative values - the mixture is rich (a lot of gasoline and little air)
Positive values - the mixture is poor (little gasoline and a lot of air)
Reasons for a rich mixture: high fuel pressure, leaky injectors (pour a lot of fuel, do not hold the pressure), the coolant temperature sensor, incorrect operation of check valves in the crankcase gas ventilation system and fuel tank ventilation (adsorber).
Reasons for poor sweep: leaky intake tract, insufficient performance of the fuel pump or injectors, low pressure in the fuel ramp, incorrect operation of the mass flow sensor or the pressure sensor in the intake manifold.
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In my case there were 2 reasons for the rich mixture:
1) fuel filter, replaced with the original one.
2) poor ventilation of the fuel tank, most likely a clogged adsorber, since the adsorber valve is serviceable,
Values in the 32 additive group at idle until filter replacement -10%..-11%, after -4%..-5%
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How to check the canister valve - disconnect it from the wiring and hoses in the disabled state, it shall be BLOWN, if blown, then it needs to be replaced, part number VAG 06E906517A , the original is BOSCH 0280142431
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