Car cranks but no start sometimes

[bayzoo]

Kia Picanto 2009 1L G4HE engine - 45k miles. Car sometimes cranks but doesn’t start, and if it press the accelerator pedal at the same time when starting and I have this issue it does start.

There are no fault codes and it happens if the car is either warm or cold. I’m thinking it could be a fuel delivery issue but it’s done this for a few years (this was my mother in laws car and I’ve I love you rede toy taking ownership).

Any idea where I’d best start trying to fault find?

AI is telling me it could be the IAC valve, MAF, or it even the crankshaft position sensor.