fuel pressure

Gonna try to keep this short. Bought a Vectra 2009 from my neighbor for cheap. Car started but ran rough, stalled after 1min. Got worse and worse and eventually didn’t want to start. So I opened up the fuel pump and that was chaos, the oil gasket had been pushed towards the engine and pump...

Basically im trying to find if my pump is knackered. Desired pressure on opcom is 5000kpa which its actual fluctuates just a little above and below. When demand is needed it will meet desired untill about 5000rpm then drop right down. Car runs fine unless i demand more then i will get the p1191...