2002 Corolla starting problem (actually Chevy Prizm)

I have a 2002 Chevy Prizm (mostly Corolla but some Chevy mods). I know it's going to need the timing chain soon but recently it suddenly just stopped running. It did start again but only for a minute but now doesn't run. I know the timing chain is becoming an issue, I can't find my compression gauge so I haven't checked the compression. I did do some checking with the fuel system and if I try to release the fuel pressure nothing come out. I disconnected the fuel hose from the pressure release valve and tried to turn the car over and no fuel came out. I checked the voltage at the pump and in the start position it gets power but in the run position there's no power to the pump. Does the pump get voltage through the computer when the engine is actually running and cuts power when the engine stops running? My thought is it's the pump since no fuel is going to the engine in the start position but the pump does get power in the start position. I'm confused why if the engine isn't running and the key is in the run position there is no power to the pump.