UK Car Repair Questions? Ask a Mechanic for Answers ASAP
This could be a wiring issue as things tend to expand when hot and its possible a poor or partial electrical connection is being pushed apart on one of the major sensors so check the connection plug and wiring to the following;Airflow meterCrank position sensorCam position sensorO2 sensorThrottle position sensor
unplug each in turn and use some switch / contact cleaner spray on the pins to ensure its all grease / dirt free
Also worth checking the connections to the fuel pump for the same reason - unplug each in turn and give them a good squirt of switch / contact cleaner - Not WD40
and also unplug and inspect the main power relays and fuses for signs of overheating or corroded terminals - so the ones for the ECU and the fuel pump
And also unplug the wiring loom connections in the engine bay one at time and inspect for corroded or recessed pins.
you're right in saying that it could be quite a few things, which is why I suggest a route of checking and testing likely candinates
a faulty , sticking fuel pressure regulator is strong possibilty though so 1st thing to try some injector cleaner into the fuel