Page 197 - Understanding Automotive Electronics
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2735 | CH 5  Page 184  Tuesday, March 10, 1998  11:10 AM



                5                    THE BASICS OF ELECTRONIC ENGINE CONTROL




                                       9. What is the desired operation of a   14. What is the function of electronic
                                         catalytic converter on HC          fuel control in a vehicle having a
                                         emissions?                         three-way catalyst?
                                         a. oxidation to H O and CO 2       a. to maximize brake-specific
                                                         2
                                         b. reduction to H and C                fuel consumption
                                         c. reaction with NO x              b. to maintain the average air/
                                         d. none of the above                   fuel ratio at stoichiometry
                                                                            c. to always keep the air/fuel
                                      10. What is the desired operation of a
                                                                                ratio within ±0.05 of
                                         catalytic converter on NO
                                                              x                 stoichiometry
                                         emissions?
                                                                            d. to minimize NO  emissions
                                                                                              x
                                         a. reaction with HC
                                         b. oxidation to N  and O 2      15. What is the fuel flow rate for an
                                                         2
                                         c. reduction to N  and O 2         electronic fuel control system for a
                                                         2
                                         d. none of the above               vehicle having a three-way catalyst?
                                                                            a. R  = R /14.7
                                                                                 fm
                                                                                      m
                                      11. What is stoichiometry?            b. R /14.7
                                                                                 a
                                         a. a very lean air/fuel ratio      c. R  – R EGR /14.7
                                                                                 v
                                         b. a very rich air/fuel ratio      d. none of the above
                                         c. an air/fuel ratio for which
                                             complete combustion is      16. What engine quantities are
                                             theoretically possible         measured to determine spark
                                                                            advance for an electronic ignition
                                         d. none of the above
                                                                            system?
                                      12. How is CO emission affected by    a. manifold pressure, RPM, and
                                         air/fuel ratio?                        temperature
                                         a. it generally decreases with     b. coolant temperature and mass
                                             increasing air/fuel ratio          air flow
                                         b. it increases monotonically      c. manifold position and
                                             with air/fuel ratio                crankshaft position
                                         c. it is unaffected by air/fuel    d. none of the above
                                             ratio                       17. In an electronic fuel control
                                         d. none of the above
                                                                            system, what causes the time delay
                                      13. What is MBT?                      between fuel metering and the
                                         a. mean before top-center          EGO sensor response?
                                         b. miles per brake torque          a. dynamic response of the
                                         c. mean spark advance for best         electronics
                                             torque                         b. transport time of the air and
                                         d. none of the above                   fuel through the engine
                                                                            c. limit-cycle theory
                                                                            d. none of the above





                184                  UNDERSTANDING AUTOMOTIVE ELECTRONICS
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