1992 Lumina starting problem

Check injectors stuck open and check FPR

Fuel Pressure Regulator (PFI)
Fuel pressure regulator on PFI systems is a diaphragm-operated relief valve with injector pressure on one side and manifold pressure (vacuum) on the other. Pressure regulator compensates for engine load by increasing fuel pressure when low manifold vacuum is experienced.
During periods of high manifold vacuum, regulator-to-fuel tank return orifice is fully open, keeping fuel pressure on the low side of its regulated range. As throttle valve opens, vacuum to regulator diaphragm decreases, allowing spring tension to gradually close off return passage. At wide open throttle, when vacuum is at its lowest, return orifice is restricted, providing maximum fuel volume and maintaining constant fuel pressure to injectors.