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Engine Controls - Tests W/o Codes - 3.0L: Other Mercury Sable III

Testing & Diagnostics ~940 words

Preliminary Checks

Check battery connections. Check starter relay connections. Check all fuse links. On A/T models, ensure gearshift is in Park. On M/T models, ensure clutch is fully depressed. If vehicle is equipped with anti-theft devices, ensure system is deactivated.

Check for vacuum leaks. Check fuel quality. Check air cleaner/air intake duct.

Check for vacuum leaks. Check fuel quality. Check for restricted air filter/air intake duct. Check wiring harness connectors.

Check fuel quality. Check Inertia Fuel Shutoff (IFS) switch. Check alarm/anti-theft devices. Check wiring harness connectors. Check for disconnected or restricted air intake duct. Check fuses and relays.

Check for vacuum leaks. Check throttle linkage operation. Check air intake system. Check throttle body.

Check for vacuum leaks. Check air intake duct. Check air filter. Check primary and secondary ignition wiring harness and components. Check for cracked or missing cooling fan blades.

HIGH IDLE (DIESELS/RUNS ON)

Note. If engine is overheating, go to ENGINE RUNS HOT symptom. If engine runs cold, go to ENGINE RUNS COLD symptom.

Check for vacuum leaks. Check for carbon build-up on throttle plate. Check throttle linkage operation. Check for binding/sticking cruise control chain. Check air intake duct. Check for leaking intake manifold gasket.

Check Idle Air Control (IAC) wiring harness connector. Check base timing. Check engine mechanical condition.

HESITATES OR STALLS

Note. The PCM is equipped with an over RPM/speed limit function. If programmed speed is exceeded, fuel delivery will shut off and DTC P1270 will be set in PCM memory.

Check for vacuum leaks. Check fuel quality. Check for restricted air filter/air intake duct. Check wiring harness connectors.

Check for vacuum leaks. Check fuel quality. Check for restricted air filter/air intake duct. Check wiring harness connectors.

Check vacuum hose routing. Check spark plug wiring for incorrect firing order.

LOSS OF POWER

Note. The PCM is equipped with an over RPM/speed limit function. If programmed speed is exceeded, fuel delivery will shut off and DTC P1270 will be set in PCM memory.

Verify symptom is reported under normal driving conditions without engine under excessive load conditions. Check vacuum hose routing. Check for restricted air filter. Check wiring harness connectors. Check for obstructed radiator. Check transmission fluid.

Check vacuum hose routing. Check for restricted air intake system. Check engine oil and fuel quality.

POOR FUEL ECONOMY

Note. Fuel consumption will increases during stop-and-go driving, trailer towing, short-run operation, extended winter warm-up periods, etc. Determine if these factors are the cause of poor fuel mileage before proceeding with diagnostic procedure.

Check for restricted air filter/air intake duct. Check transmission fluid level. Check fuel quality.

EMISSIONS COMPLIANCE

Canada and some states or metropolitan areas in the United States require periodic idle emission tests. All Ford products have been designed to pass these tests. If a Ford product fails an idle Emission test, it is probable that the engine temperature was not warm and stabilized prior to the test or the vehicle had idled excessively long prior to the test. Before starting any services, verify complaints of idle emission test failure.

The following encompasses most of the emissions measurement modes of current state idle test procedures

  1. Ensure engine is at normal operating temperature and all accessories are turned off.
  2. Check emissions at idle.
  3. Operate engine at 2200-2800 RPM.
  4. Check emissions within 30 seconds.
  5. Return engine speed to idle.
  6. Check emissions within 30 seconds.

If any emission component is changed, Keep-Alive Memory (KAM) should be cleared before repeating state emission test procedure. See the TESTS W/CODES - 3.0L article. To relearn adaptive strategy, operate engine at 2500 RPM for one minute. Operate engine at idle speed for 2 minutes.

Check for vacuum leaks/blockage. Check wiring harness connectors.

Check transmission fluid level and condition. Check for transmission leaks. Check wiring harness connectors. Check for vehicle modifications. Check for electronic add-on items. Check for misadjusted shift linkage.

Check for external engine oil leaks. Check for proper oil dipstick. Check for proper oil viscosity.

Check coolant level. Check for coolant leaks. Check fan belt. Check radiator fan connectors. Check water/anti-freeze mixture. Check radiator condition. Check for collapsed/restricted radiator hose. Check radiator cap. Check overflow system.

Check radiator cooling fan operation.

Black Smoke (Rich Mixture)

  1. Check for restricted air cleaner/air intake duct.
  2. Check for restricted fuel return hoses.
  3. Check ignition system. See CIRCUIT TEST JD in «TESTS W/CODES - 3.0L»(ref-24094) article.
  4. Check fuel delivery system. See CIRCUIT TEST HC in «TESTS W/CODES - 3.0L»(ref-24094) article.

Blue Smoke (Burning Oil)

  1. Check PCV system. See CIRCUIT TEST HG in «TESTS W/CODES - 3.0L»(ref-24094) article.
  2. Check engine mechanical condition. Check valve guides, valve stems, valve seals, oil drain passages in cylinder heads (Blue smoke on start-up), piston rings and cylinder bores.

White Smoke (Water In Combustion)

  1. Check for cylinder head gasket leaks, intake manifold gasket leaks and cracked engine block.

Check fuel system and EVAP system for leaks.

Check fuel system and EVAP system for leaks.

Squeal, Click Or Chirp

  1. Check for low oil level.
  2. Check valve train components.
  3. Check drive belts.
  4. Check EEC-V solenoids.

Hiss

  1. Check for cooling system leaks.
  2. Check for vacuum leaks.
  3. Check for loose spark plugs.
  4. Check for air intake leaks.
  5. Check for secondary air injection leaks.
  6. Check for Evaporative Emission (EVAP) system leaks.

Snap

  1. Perform a visual/audible check of secondary ignition system.

Rap Or Roar

  1. Check for exhaust leak.
  2. Check for secondary air injection leaks.

Knock

  1. Check for worn rod/main bearings.
  2. Check for loose piston pins.
  3. Check piston to cylinder bore clearance.
  4. Knock (Detonation) - See SPARK KNOCK under SYMPTOMS.

Perform a visual inspection of A/C system. Check A/C switches. Check fuses.

Check for shorted A/C wiring. Check A/C heater control. Check A/C compressor.

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