I am waiting on a new fuel pressure sensor but in the meantime, I tried a few things.
First was to try heating some of the suspected components with a hairdryer while the engine was cold to see if I could induce the fault. I tried the fuel pressure sensor, throttle body and mass airflow sensor but didn't notice any change. I don't think a hairdryer is suitable for this purpose as I couldn't get things very hot.
I then removed the intake manifold to get ready for the new fuel pressure sensor (FPS). This also gave me a chance to have a look at the throttle body (ETM).
Unfortunately, it looks like someone has been in there before and replaced the ETM (electronic throttle module) with a used part. This could mean that someone has tried to fix the problem and given up. What hope is there for me I wonder?
I have given it a clean (two before and two after shots below) but it was already pretty clean so I don't expect any change.
I will report back once the FPS arrives and is fitted.