Engine Performance Final Exam Graded A+

The acceptable amount of alcohol mixed with gasoline (non E-85) is: - ANSWER-Up to 10 percent. When the pressure in the intake manifold increases, the fuel pressure regulator on a port fuel injection system: - ANSWER-Increases fuel pressure. Technician A says to relieve pressure on an PFI (port fuel injection) system, a pressure gauge may be connected to the fuel pressure test port and the bleed (pressure relief) valve on the gauge opened with the bleed hose installed in an approved container. Technician B says before fuel system components on an PFI system can be removed, the fuel system pressure must be relieved. - ANSWER-Both A and B Technician A says fuel that has low volatility can cause a buildup of deposits in the combustion chamber. Technician B says liquid gasoline will not burn. - ANSWER-Both A and B Technician A says a fuel rail holds all the injectors on a PFI equipped engines. Technician B says a PFI fuel injection system sprays fuel into the intake port near the intake valve. - ANSWER-Both A and B Technician A says the fuel rail delivers fuel to the fuel injectors. Technician B says the throttle body in a port fuel injection system controls the amount of fuel entering the engine. - ANSWER-Technician A The fuel pressure regulator in return-type fuel systems is located: - ANSWER-At the outlet of the fuel rail. Technician A says a rich air-fuel mixture may be the result of higher-than-normal fuel pressure. Technician B says higher-than-normal fuel pressure causes a lean air-fuel ratio. - ANSWER-Technician A Higher-than-normal fuel pressure may be caused by: - ANSWER-Both A and B A defective fuel pressure regulator. A fuel return line that is restricted.