ASE 8 Engine Performance Study Questions and Answers

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