Outer Limits 4x4 Board

Hi guys, some helpful people on here have been great making suggestions but still stumped.

Initial problem...
going up a big hill or just after a smaller one, it would start to run rough like it was out of fuel and die.
wait 10-15mins it'd start back up again, after a bit of a cough, and then it'd run very smooth like normal.
as long as it was still on flat, all good. go up a hill again and it'd die.

now it just dies randomly and has nothing to do with hills, give it 20 mins or so.
after a decent wait it'll start but it requires heaps of rapid pumping of the accelerator while it coughs and splutters (stop pumping the accl and it'll die) before it eventually just starts running fine and revs freely.etc

things checked amongst the normal.:
swapped fuel tank, fuel filter, new fuel pump, power to pump, vac pressure reg, airfilter.etc

it's been to a mech who had it for a couple of weeks and also tried things but still it's a no go.
and now it's really no go and doesn't really start at all haha..

any ideas?
just throw whatever you've got please. any help appreciated.
also anyone with spare parts like OBComputer would be a champ if available to test out too.

cheers.

i would definately be checking the air flow meter and inlet plumbing.

if a hot wire air flow meter is even very dusty it can play games

Air Flow Meter or Crank Angle Sensor.