Engine Controls - Tests W/o Codes: Other Ford Bronco V

Preliminary Checks

Check battery connections. Check starter relay. Check alarm/anti-theft devices. Check fuses and fusible links. Check all electrical loads (headlights, radio, etc.). On A/T models, ensure gearshift is in Park. On M/T models, ensure clutch is fully depressed.

Check for vacuum leaks. Check fuel quality (octane, winter/summer grade fuel, methanol, etc.). Check air intake system and air cleaner for leaks and/or restrictions.

Check for vacuum leaks. Check fuel quality (octane, winter/summer grade fuel, methanol, etc.). Check air intake system and air cleaner for leaks and/or restrictions. Check wiring harness connectors.

NO START/NORMAL CRANK

Note. Extended cranking, due to no-start condition, can load the exhaust system with raw fuel, which can ruin the catalytic converter after the engine is started. After servicing no-start condition, disconnect secondary air supply, operate engine until surplus fuel is used up, and then reconnect secondary air supply.

Check Inertia Fuel Shutoff (IFS) switch. Check fuel pressure and quality (octane, winter/summer grade fuel, methanol, etc.). 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. Check air intake system. Check throttle body.

Check ignition and wiring harness connectors. Check air intake duct. Check for vacuum leaks. Check for cracked or missing cooling fan blades. Check for broken motor mounts. Check for contaminated air filter.

Check for vacuum leaks. Check Idle Air Control (IAC) solenoid connections.

HESITATES OR STALLS

Note. The Powertrain Control Module (PCM) is equipped with an over RPM/speed limiting function that will shut off fuel delivery when predetermined speed is exceeded.

Check vacuum hose routing. Check for restricted air filter/air intake duct. Check fuel quality (octane, winter/summer grade fuel, methanol, etc.). Check ignition and wiring harness connectors.

Check vacuum hose routing. Check for restricted air filter/air intake duct. Check fuel quality (octane, winter/summer grade fuel, methanol, etc.). 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 RPM/speed limiting function that will shut off fuel delivery when predetermined speed is exceeded.

Verify symptom occurs under normal driving conditions without engine being 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 filter. Check fuel quality (octane, winter/summer grade fuel, methanol, etc.).

POOR FUEL ECONOMY

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

Check for restricted air filter/air intake duct. Check transmission fluid level. Check fuel quality (octane, winter/summer grade fuel, methanol, etc.).

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 idle emission test, it is probable that engine temperature was not warm and stabilized prior to the test, or vehicle had idled excessively for long period prior to the test.

Before starting any services, verify complaints of idle emission test failure by using test procedure of area that failed vehicle. 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. To clear KAM, disconnect negative battery cable for at least 5 minutes.

Check for vacuum leaks/blockage. Check wiring harness connectors for clean, tight fit. Ensure vehicle scheduled maintenance is current.

Determine which warning indicator lights are used in vehicle.

Preliminary Check

Check transmission fluid level and condition.

Note. The following symptom checks are for A4LD, AXODE, AODE and E4OD transmissions only.

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

Check coolant level. Check fan belt. Check electric cooling 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)

Perform the following

1. Check for restricted air cleaner/air intake duct.
2. Check for restricted fuel return hoses.
3. Check ignition system. See IGNITION SYSTEMS in «I - SYSTEM/COMPONENT TESTS»(ref-22986) article in the ENGINE PERFORMANCE section.
4. Check fuel delivery system. See FUEL SYSTEM in «I - SYSTEM/COMPONENT TESTS»(ref-22986) article in the ENGINE PERFORMANCE section.
5. Check fuel control circuit. See step 2) of CIRCUIT TEST H in «TESTS W/CODES - EEC-IV»(ref-22952) article in the ENGINE PERFORMANCE section.

Blue Smoke (Burning Oil)

Perform the following

1. Check PCV system. See EMISSION SYSTEMS & SUB-SYSTEMS in «I - SYSTEM/COMPONENT TESTS»(ref-22986) article in the ENGINE PERFORMANCE section.
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)

Perform the following

1. Check engine mechanical condition. Check for cylinder head and intake manifold gasket leaks. Check for cracked/porous cylinder head and engine block.

Check wiring harness connectors and vacuum hose routing. Since sulfur content varies in different fuels, try a different brand of fuel.

Some slight sulfur smell may be normal. Catalysts with less than 5000 miles are more likely to have a sulfur smell due to its highly active state. Replacing catalyst, may make this symptom worse.

Squeal, Click Or Chirp

Perform the following

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

Hiss

Perform the following

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 air injection leaks.
6. Check for Fuel Evaporation (EVAP) system leaks.

Snap

Perform the following

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

Rap Or Roar

Perform the following

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

Knock

Perform the following

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

Perform a visual inspection of A/C system, including compressor drive belt and hoses. Check A/C switches. Check fuses.

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

Check if A/C system turns off when A/C system demand switch is turned off. If not, go to A/C SYSTEM ALWAYS ON symptom.

Ignition Timing

1. Turn ignition off. Place transmission in Park or Neutral. Turn off all electrical loads. Disconnect in-line Spark Output (SPOUT) connector. Start engine (DO NOT use a remote starter).
2. Start engine and warm to normal operating temperature. With engine at idle speed, check initial (base) timing.
3. Turn ignition off. Reconnect IAC solenoid or single-wire SPOUT connector. Check ignition timing advance to verify distributor is advancing beyond initial setting. Disconnect test equipment. NOTE: Electronic Ignition (EI) low data rate and high data rate systems cannot be adjusted. Check Camshaft Driven (CMP) Hall sensor, synchronizer sensor orientation, timing belt/chain, etc.
4. If timing is not within 2 degrees of specification on emission label, adjust timing as necessary. If unable to adjust timing to specification, check engine mechanical condition (distributor orientation, timing belt/chain, etc.).

Intermittent Simulation

To reproduce the conditions creating an intermittent fault, use the following methods

1. Lightly vibrate component.
2. Heat component.
3. Wiggle or bend wiring harness.
4. Spray component with water.
5. Remove/apply vacuum source.

Note. For test equipment connection and continuous monitor mode test operation, see CONTINUOUS MONITOR MODE (WIGGLE TEST) in TESTS W/CODES - EEC-IV article in the ENGINE PERFORMANCE section.