D5 (D5244T to 2005) Low Speed Loss of Boost. Takes along time to buildup.

[cheshired5]

Originally Posted by tomkirkland

Sirobbs channel has helped me out no end with bits and bobs.

The latest video includes a complete service and cleaning of the Euro 3 D5 EGR actuator, valve and cooler.
Looking at the state of the front EGR mixer pipes is no indication of the the EGR valve performance at the back so you'll need to delve much further.

Also the fact that you cannot get a stable vacuum reading directly from the vacuum pump suggests the vacuum pump as the root cause then the resulting poor running of the engine produces excess smoke which in turn has likely coked up the EGR.

The location of the MAP sensor means that it will likely be filthy too.

The Euro 3 vacuum pump has no official service kit so prepare to replace it which fortunately shouldn't cost much as they are cheap from breakers due to low demand as they're generally reliable.

The airflow readings suggest that the airflow part of the MAF sensor is fine but do monitor IAT readings.
The IAT sensor is built into the MAF so if that is defective, the whole MAF sensor needs changing.
Once again not expensive to buy used genuine Volvo/Bosch working MAFs. £20-30