[Prefferle]

Hi guys,

Update - connected VCDS and monitored fuel trim so bank 4 (cyl9 and cyl10) is measuring way out with long term fuel trim up to 25 fluctuating between 23 and 25... I believe this should be below 10 as on the other banks...

I did clamp off vacuum pipes and doused a whole can of carb spray around the inlet manifold, breather and various vac pipes - no change in fuel trim readings.

Interestingly I pilled dipstick and change in readings as expected. Couldn’t even remove the oil filler cap - hadn’t realised the vacuum was so extreme at idle...

With the other 3x banks fine the problem looks localised so I’m guessing not a vacuum leak as that would likely affect more banks since this engine although two throttle bodies has a common inlet manifold chamber.

Figuring this means a mixture problem so either an ignition / injection / compression problem on 9 and 10.

Anyone have deeper understanding of VCDS as I’m sure there must be other parameters that will help focus on the actual fault?

Thanks guys for any ideas.... time for a cuppa.