The car : EG Hatch Civic with Accord H22A7 Motor fitted

Mods : Totally standard apart from uprated Walbro fuel Pump

Issue : When theres anything above half a tank of petrol in the tank, within 2 minutes of driving the car, it kangaroos like mad. The only way ive found out to cure the problem is to leave the car running, unplug the throttle position sensor, rev it once or twice, then refit the plug onto the throttle positon sensor. From then on the car has no running issues at all?

Im thinking it could be some sort out pressure issue in the tank. Can anyone shed some light on this, or has anybody come across this before?

Thanks, Matt