3 plug VTS - won't idle or rev above 4.5k

[Liam_]

The car starts but cuts out straight away. If I hold the throttle, the car runs fine, but dies as soon as I let go. It's also unable to rev above 4.5k - car abruptly stops accelerating and the handbrake light comes on for a split second. I haven't checked for fault codes yet, but the EML is not on.

What I've done/ tried so far:
Replaced timing belt (timing is fine)
Replaced engine loom
Replaced ECU
Replaced coolant temperature sensor
Brand new coil pack (originally had the same issue accompanied with a P0300 random multiple misfire - new coil pack and clearing the fault code has fixed the misfire issue)
I've also tried a known working ICV, MAP sensor, and crank sensor
Replaced fuel filter

The only thing I'm really left with is the fuel pump. It may be coincidence, but the fuel gauge often switches from the correct reading to full or empty. I've had a few Saxos and it sounds quite tired when priming compared to those - almost like the battery is going flat.

Hoping to pick up a replacement pump this weekend, but any input appreciated.

Danke

[Ashcollings02]

have u checked fuel pressure ?

[stevo67]

Throttle position sensor(back off the throttle body)