Ok so I have started the car after work with the MAF removed. Left it running for a while, turned off the engine, reconnected the MAF and now it seems fine?

Admittedly it was only idling but it was revving right up to the limiter (and IMRC was functioning correctly!!)

I have bought a new fuel filter anyway so tomorrow will change this. Along with disconnecting battery for a while and cleaning the inlet.

I plan to check as much wiring as possible around the fuel rail area in case there's anything obviously damaged.

Am I best to fill the petrol up before attempting the filter so any sediment in the tank is not likely to go through the new filter??