Passat 3B: V6 TDI AFB - Power Loss & Fuel Consumption

Hello everyone,
Fantastic forum. Thank you, Rainer, for all your hard work.

'I'm experiencing a problem with my Passat 3B V6 TDI (AFB), manufactured in January 1999, with 98,000 km on the odometer. Recently, I've noticed that at speeds of around 150 km/h on the highway, the engine power suddenly drops during acceleration (it seems like the torque converter lock-up clutch is disengaging!). This also happens occasionally when accelerating from low RPMs. Additionally, I've subjectively observed poorer starting behavior and slightly increased fuel consumption...'

Fault code: 00550 Control difference injection start (occurs sporadically).

I've already read the relevant articles here, and I will inform the workshop next week about the following: fuel supply (air, pre-pump?), valve injection timing N108, needle lift sensor G80, start of delivery.

I'm also thinking about getting the timing belt changed soon, because a basic adjustment is usually done at the same time, right?

I will keep the forum updated.

Hi,
Okay, so it seems the issue with the torque converter bypass isn't related to the transmission itself. Rather, it appears that not enough fuel is being injected, which results in insufficient power output. The engine control unit (ECU) then likely tries to compensate for this by increasing the engine speed...

The cold start problems have worsened significantly since November. After being idle for a longer period, the engine now almost always goes into limp mode after starting (visible by the indicator light for the automatic transmission). It then works again after turning it off and restarting.

By the way, there was a lot of white smoke when I started it.

He's currently at the repair shop (VAG), and I spoke with the mechanic earlier. He said the fuel injection pump is broken, and he blamed it on the biodiesel. *Sigh*.

He can't check the timing belt because he can't easily access it. However, I still ordered a timing belt replacement; it's only supposed to be replaced every 20,000 miles (the car currently has 100,000 miles on it).

The new fuel injection pump is supposed to cost €1500, which I find too expensive for now. I'll probably buy a VAG-COM diagnostic tool first.

Is a fuel consumption of 9 liters per 100 kilometers at speeds of 150-160 km/h on the highway too high, or rather normal for this car (with an automatic transmission)?

Best regards,
Christian.