Yeah I couldn’t believe it either - there is some link but can’t remember how I found it now
Might not be your issue but worth checking to save your sanity!
In my Td4 180 Discovery Sport HSE auto I had, I used to get around 38-40 mpg and I don’t drive gently and spent a lot of time on M20/M25 as well at that.
Never driven the manual version so unsure on its real world values.
Inertia switch is located inside the restraints control module (airbag ecu)
There is a fuel pump driver module on those models and I can’t remember where it is located
What issue are you having?
Check the exhaust valve is plugged in correctly - I had similar when replacing a compressor and it was the exhaust valve connector not pushed fully home - looked alright but wasn’t making the electrical connection
I never lifted the engine when I did mine on a Td4 - you have to take the pulley off and strip pump from bracket etc to avoid it.
Long time ago when I did it and can’t remember the full ins and outs now
You need either WFX000210 for chassis 3A000001 onwards and 2A209163 - 2A359999
Or WFX000190 for 1A333159 to 2A209162 and 2A3600001 to 2A399999
Need to check your VIN to verify
What part number is currently fitted do you know?