going to throw this to the wider community as i am stumped...
i cannot get to the bottom of this fault.... so background.
Car is at 134k. good condition.
Things done -
Cambelt, thermostat. Timing is verified as 100% accurate
New injectors and new (secondhand) fuel rail (replaced as the Schrader valve broke off on the old one. I cannot verify the fuel pressure on this
New 4 bar fuel filter
New MAP sensor
New lambda sensors (both of them)
New spark plugs
New plug leads
New Coil Pack
New EGR valve
SAI system works and the N80 is airtight, charcoal cannister is empty and has no excess fuel in it
G62 coolant temp is registering the correct values
There are no air leaks
There are no exhaust leaks
On the electrical circuit the common 5v single is all present and correct and the MAP sensors shows the correct mV reading at idle
Injector timing at idle is 2.06m/s
MAP sensor reading at idle is 377mBar (high but not excessively so)
on measuring block 030 (VCDS) you can see the car try to stay open loop lambda control but then it reads the lambda control on block 033 lambda control is -27.7% so massively over fuelling and then goes closed loop.
the one way valve between the cylinder head and brake booster is working and the booster holds vacuum.
an ecu reset has been done multiple times as has a throttle body alignment, the smoking gun here is every once in a while it does throw up a fault that the TBA is not aligned but i can't track that issue down yet.
Yet this fault persists and i cannot get it through an MOT as the car fails on emissions (no i don't want to get a dodgy MOT lol)
i'm stumped and would welcome other minds to bounce ideas off of or if anyone has seen this before?
i cannot get to the bottom of this fault.... so background.
Car is at 134k. good condition.
Things done -
Cambelt, thermostat. Timing is verified as 100% accurate
New injectors and new (secondhand) fuel rail (replaced as the Schrader valve broke off on the old one. I cannot verify the fuel pressure on this
New 4 bar fuel filter
New MAP sensor
New lambda sensors (both of them)
New spark plugs
New plug leads
New Coil Pack
New EGR valve
SAI system works and the N80 is airtight, charcoal cannister is empty and has no excess fuel in it
G62 coolant temp is registering the correct values
There are no air leaks
There are no exhaust leaks
On the electrical circuit the common 5v single is all present and correct and the MAP sensors shows the correct mV reading at idle
Injector timing at idle is 2.06m/s
MAP sensor reading at idle is 377mBar (high but not excessively so)
on measuring block 030 (VCDS) you can see the car try to stay open loop lambda control but then it reads the lambda control on block 033 lambda control is -27.7% so massively over fuelling and then goes closed loop.
the one way valve between the cylinder head and brake booster is working and the booster holds vacuum.
an ecu reset has been done multiple times as has a throttle body alignment, the smoking gun here is every once in a while it does throw up a fault that the TBA is not aligned but i can't track that issue down yet.
Yet this fault persists and i cannot get it through an MOT as the car fails on emissions (no i don't want to get a dodgy MOT lol)
i'm stumped and would welcome other minds to bounce ideas off of or if anyone has seen this before?
