If the pump is running pull the inlet hose and put a can under it hold it and have somebody else try to start the gas should run out if it doesn't their is a primer pump in the fuel tank.
I think this year system has a pressure regulator on the fuel rail pull the vacuum hose and if fuel is observed replace the regulator.
You can use a pair of vise grips and pinch off the return hose back by the fuel tank. If it runs a lot better replace.
The inertia switch shuts off power doesn't lower voltage.
I would verify you have spark hold the plug against the motor to make sure it fires.
These vehicles will start with starting fluid if the pump is bad spray some in the air inlet.