Next, check for a leaking fuel-pressure regulator. A leaking regulator (usually caused by a ruptured internal diaphragm) can allow raw fuel to be drawn through the vacuum line and into the intake.

Knowing how your car's fuel pump operates is always helpful, but here are very convenient ways to check if it is broken or has stopped working.

A fuel-pressure regulator at the end of the second fuel rail pinched off fuel flow back to the gas tank to regulate the fuel pressure. This system was used until 1998.