Chapter 5, Problem 5.100EP

A 1. How does the octane number (O.N.) of the fuel a. Higher ignition advance is required for a high O.N. fuel. b. Higher ignition retard is required for a high O.N. fuel. affect spark ing:d. Nou does not affect spark timing. c. The octane number 2. How does the ignition system account for load change? these. of a. The throttle b. The vacuum ignition governor c. The mechanism of d. None of is wide opened. provide additional spark advance at part throttle positions. centrifugal advance does the job. these. 3. In the common rail fuel system the fuel is metered by ........ a. low pressure pump. b. injectors. c. high pressure pump. d. none of these. 4.......... is the time period, measured in degrees of cam rotation, during which the contact points remain closed between each opening. a. Distributor. b. Dwell. c. ECU. d. none of these. 5. The trigger wheel in TCI system replaces the ......... used in a contact breaker distributor. a. pickup coil. b. distributor cam. c. condenser. 750 x2.01…

a い يكا 4 +91- pu Answer the following statements by true or false, giving the reason for your answer: 1. Injection pressure in CI engines should be sufficiently high. 2. The purpose of the condenser in battery ignition system is to prevent spark in the ignition coil assembly. 3. An idling engine requires lean mixture of fuel and air. 4. Factors which decide optimum engine firing order are engine vibration, engine cooling and back pressure. 5. It is the duty of the header to control over speeding during CI engine operation when drastic reduction in load occurs. ---20125 750 x2.01 SP

6. The Pre-combustion chamber design engines employ nozzle type commonly referred to as a a. inward-opening nozzle b. multiple-hole nozzle. c. pintle nozzle. d. none of these. 7. If the temperature of the spark plug tip is less than 350 °C, ........ a. the plug might b. the carbon deposits not work. would increase. c. pre-ignition will occur. d. none of these. 8. Port injection sprays fuel........ a. towards the intake valve. b. in the engine cylinder. c. in the throttle body d. none of assembly. these. 9. When the fuel-air mixture changed from best power to a richer ratio, the spark advance should be ........ a. increased. b. decreased. c. left unchanged. d. none of these. 10. Spark plugs are classified as hot plugs and cold plugs depending upon a. spark gap. b. the type of plug c. the operating temperature d. none of these. range of the electrode tip. insulator.