ASE 8 Engine Performance Exam Solved

High Hydro Carbons indicate... - ANSWER-Engine misfire; Incomplete burning of fuel, Ignition fault Lean misfire Thermostat (engine temp. too low) High CO indicates... - ANSWER-Rich condition; Leaking fuel injector or fuel-pressure regulator Clogged air filter or PCV system Excessive fuel pressure High NOx indicates... - ANSWER-Hot engine temp. Bad EGR valve Lean Air/Fuel mixture High Compression If vacuum is low, EGR flow is_______? - ANSWER-High A cold engine requires a (Rich, or Lean) Air/fuel mixture? - ANSWER-A engine with low coolant temperature requires a rich A/F mixture. When the engine is under heavy load, intake manifold vacuum is_____ and fuel pressure is_____. - ANSWER-Vacuum is low and fuel pressure is higher. When the engine is at idle or cruise, intake manifold vacuum is _______ and fuel pressure is________. - ANSWER-Intake vacuum is high and fuel pressure is lower. Primary ignition system - ANSWER-Battery Ignition switch Primary windings Pick up coil (crank sensor) PCM Ignition module secondary ignition system - ANSWER-High voltage (tension); secondary windings on coil, distributor cap, spark plugs, spark plug wires If EGR valve is not open.... - ANSWER-Symptoms; Knocking during acceleration or cruising Excessive NOx If the EGR valve is stuck open... - ANSWER-Symptoms; Rough idle Frequent stalling