C16xe fuelling issues

Just on with putting my nova back together after about 5/6 years of been stood, took ages and ages to start, but I put that down to the lines and rail being dry, it eventually started, once switched off it took the same amount of time to start, I put this down to the fuel pump being dry for a few years. It slowly got better to the point where it now starts on the button.
My problem now is hesitation, when I set off it tries to die, lightly press the accelerator up-to about 2k and all's good, but under its bad and I haven't even got it out on the road yet, I think it's fuel starvation, the exhaust is getting red hot straight away as if it's very lean, I'm swaying towards fuel pump, am I on the right lines not really had anything to do with these engines till now.

What pump is on it?

C16xe is prime for shearing crank pulley keys and retarding the timing which causes similar issues.

Pump and lines should prime within seconds

An mpi pump out of a corsa gsi, and it does prime now but it didn't for a while, which is why I was thinking fuel pump,

Do they snap keys and slip the cam timing or the pick up and slip ignition timing?

Both. The cam pulley is the one that slips, so the ign timing slips too cos the trigger wheel is driven off the crank-cam pulley

Did the belt while I had the engine out and didn't see anything a miss, might just whip covers off and check everything for peace of mind

Worth checking if youve been over everything. Often happens after the belts changed as people struggle to get the crank nut tight enough. You have to really look close at the belt pulley as the key shears off it flush and it isnt obvious.

The fact your saying the manifold is getting roasted would suggest the timing is retarded.