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Tests W/o Codes - 4-cyl Ford Festiva I

Testing & Diagnostics ~1014 words

INTRODUCTION

Before attempting to diagnose symptoms or intermittent faults, ensure steps in the appropriate BASIC TESTING and TESTS W/CODES articles have been performed. See the following menu. Use this article to diagnose driveability problems that exist when a hard fault code is not present.

BASIC DIAGNOSIS

  1. See: «BASIC TESTING»(/ford/festiva/i-1986-1993/remont/testing-diagnostics/#basic-testing)

CODE TESTING

  1. Carbureted, see: «TESTS W/CODES - CARBURETED»(/ford/festiva/i-1986-1993/remont/testing-diagnostics/#tests-wcodes-carbureted)
  2. Fuel Injected, see: «TESTS W/CODES - MPFI»(/ford/festiva/i-1986-1993/remont/testing-diagnostics/#tests-wcodes-mpfi)

Symptom checks are intended to direct the technician to malfunctioning component(s) so that further diagnosis may be performed. A "symptom" should lead to further testing of specific components or systems, or verification of adjustment specifications.

Use intermittent test procedures to locate intermittent driveability problems that do not occur when the vehicle is being tested. These problems may cause a noticeable driveability problem or cause the "malfunction" warning light to illuminate on some vehicles.

It is also possible that certain driveability concerns have been rectified by the manufacturer through substitution of a revised calibration chip or computer control unit. Check with manufacturer for latest information on updated chips and control units.

Note. For specific system and component testing, refer to the: Carbureted, see: SYSTEM/COMPONENT TESTS - CARBURETED Fuel Injected, see: SYSTEM/COMPONENT TESTS - EFI For specifications, see: SPECIFICATIONS - 4-CYL For adjustment procedures, see: ADJUSTMENTS - 4-CYL

SYMPTOM DIAGNOSIS

Symptom checks cannot be used properly unless the problem is actually happening while the vehicle is being tested. To reduce diagnostic time, ensure steps in BASIC TESTING and TESTS W/CODES articles have been performed before attempting to diagnose a symptom. See the following menu.

  1. See: «BASIC TESTING»(/ford/festiva/i-1986-1993/remont/testing-diagnostics/#basic-testing)
  1. Carbureted, see: «TESTS W/CODES - CARBURETED»(/ford/festiva/i-1986-1993/remont/testing-diagnostics/#tests-wcodes-carbureted)
  2. Fuel Injected, see: «TESTS W/CODES - MPFI»(/ford/festiva/i-1986-1993/remont/testing-diagnostics/#tests-wcodes-mpfi)

For symptoms available for diagnosis see the SYMPTOM-TO-DIAGNOSIS MENU below.

SYMPTOM-TO-DIAGNOSIS MENU

SymptomGo To
Backfire Through Induction Or ExhaustBACKFIRES
Dieseling (Run-On)DIESELING (RUN-ON)
Lack Of PowerLACK OF POWER
Spark Knock (Pinging)SPARK KNOCK (PINGING)
Stalls/QuitsSTALLS/QUITS
Stumble/Hesitation During AccelerationSTUMBLE/HESITATION
Misses/SurgesMISSES/SURGES
Idle Is Fast/Slow Returns To IdleFAST IDLE
Idle Is RoughROUGH IDLE
Speeds UpSPEEDS UP
Cranks Normally/Won't StartCRANKS BUT WON'T START
Cranks Normally/Slow To StartCRANKS BUT SLOW START
Poor Fuel EconomyPOOR FUEL ECONOMY
Exhaust Smoke/OdorEXHAUST SMOKE/ODOR
Fuel Odor/LeaksFUEL ODOR/LEAKS
Fails Emission TestFAILS EMISSION TEST

SYMPTOM DIAGNOSIS MENU

BACKFIRES

  1. Vane Airflow Meter
  2. Idle Speed Control Solenoid
  3. Feedback Carburetor Actuator

DIESELING (RUN-ON)

  1. Idle Speed Control Solenoid

LACK OF POWER

  1. Vane Airflow Meter
  2. Wide Open Throttle Switch
  3. Exhaust Gas Oxygen Sensor
  4. A/C Thermostatic Switch
  5. Wide Open Throttle A/C (WAC) Relay
  6. Early Fuel Evaporation Heater Relay
  7. EGR Control Solenoid
  8. EGR Vent Position
  9. EGR Valve Position Sensor
  10. Idle Switch

SPARK KNOCK (PINGING)

  1. EGR Control Solenoid
  2. EGR Vent Solenoid
  3. Vane Airflow Meter

STALLS/QUITS

  1. Vane Airflow Meter
  2. Ignition Diagnostic Monitor
  3. Idle Speed Control Solenoid
  4. Pressure Regulator Control Solenoid
  5. Exhaust Gas Oxygen Sensor
  6. Engine Coolant Temperature Sensor
  7. Radiator Temperature Switch
  8. EGR Control Solenoid
  9. EGR Vent Solenoid
  10. A/C Load Control Solenoid
  11. Electrical Load Control Solenoid
  12. Early Fuel Evaporation Heater

STUMBLE/HESITATION

  1. Idle Switch
  2. EGR Control Solenoid
  3. EGR Vent Solenoid
  4. Vane Airflow Meter
  5. Early Fuel Evaporation Heater
  6. Canister Purge Solenoid
  7. Exhaust Gas Oxygen Sensor
  8. Wide Open Throttle A/C (WAC) Relay
  9. A/C Thermostatic Switch

MISSES/SURGES

  1. Exhaust Gas Oxygen Sensor
  2. Idle Switch
  3. EGR Valve Position Sensor
  4. Vane Airflow Meter
  5. Wide Open Throttle Vacuum Switch
  6. Electrical Load Control Solenoid
  7. A/C Load Control Solenoid
  8. Engine Coolant Temperature Sensor
  9. Early Fuel Evaporation Heater
  10. EGR Control Solenoid
  11. EGR Vent Solenoid
  12. Feedback Carburetor Actuator

FAST IDLE

  1. Idle Speed Control Solenoid
  2. Engine Coolant Temperature Sensor
  3. Electrical Load Control Solenoid
  4. A/C Load Control Solenoid

ROUGH IDLE

  1. Idle Speed Control Solenoid
  2. A/C Load Control Solenoid
  3. Idle Switch
  4. Electrical Load Control Solenoid
  5. Vane Airflow Meter
  6. Vane Air Temperature Sensor
  7. Canister Purge Solenoid
  8. EGR Control Solenoid
  9. EGR Vent Solenoid
  10. Engine Cooling Fan
  11. Rear Defroster Switch
  12. Headlamp Switch
  13. Blower Control Switch
  14. A/C Thermostatic Switch
  15. Neutral Gear Switch Or Clutch Engage Switch
  16. Exhaust Gas Oxygen Sensor
  17. Neutral Safety Switch

Festiva (Carb. & Fuel Injection)

  1. Idle Speed Control Solenoid
  2. Feedback Carburetor Actuator
  3. Exhaust Gas Oxygen Sensor

Tracer

  1. By-Pass Air Control Valve
  2. Coasting Air
  3. Deceleration Control
  1. Ignition Diagnostic Monitor
  2. Vane Airflow Meter
  3. Engine Coolant Temperature Sensor
  1. Vane Airflow Meter
  2. EGR
  3. Deceleration Control
  1. Ignition Module
  2. EGR Control Solenoid
  3. EGR Vent Solenoid
  4. Engine Coolant Temperature Sensor
  5. Radiator Temperature Switch
  6. Vane Airflow Meter
  1. Deceleration Control
  2. EGR
  3. EVAP
  1. Exhaust Gas Oxygen Sensor
  2. Ignition Module
  3. EGR Control Solenoid
  4. EGR Vent Solenoid
  5. Canister Purge Solenoid
  6. Feedback Carburetor Actuator
  7. Vane Air Temperature Sensor
  1. Vane Airflow Meter

EXHAUST SMOKE/ODOR

  1. Engine Coolant Temperature Sensor
  2. Radiator Temperature Switch
  3. Feedback Carburetor Actuator
  4. Vane Air Temperature Sensor
  5. Vane Airflow Meter
  6. Exhaust Gas Oxygen Sensor
  1. Evaporative Emissions
  2. Rollover Vent Valve
  1. By-Pass Air Control Valve
  1. EGR Valve Position Sensor
  2. Canister Purge Solenoid
  3. Pressure Regulator Control Solenoid
  4. EGR Control Solenoid
  5. EGR Vent Solenoid
  6. Exhaust Gas Oxygen Sensor
  1. By-Pass Air Control Valve
  2. EVAP Components

INTERMITTENT PROBLEM DIAGNOSIS

Intermittent fault testing requires the duplication of circuit or component failure, in order to identify the fault. These procedures may lead to the computer recording a fault code (on some systems) which may help in diagnosis.

If problem vehicle does not produce fault codes, it will be necessary to monitor voltage or resistance values using a DVOM while attempting to reproduce conditions which will create an intermittent fault. A change in status on the DVOM will indicate a fault has been located.

When using a voltmeter to pinpoint faults, monitor voltage reading with ignition on, or vehicle running. A change in status on the voltmeter while performing intermittent "Test Procedures" will indicate area of fault.

When using an ohmmeter to detect problems in the circuit, monitor circuit resistance (ohms) with ignition switch in the "OFF" position, or with battery disconnected. A change in ohmmeter reading while performing "Test Procedures" will indicate area of fault.

TEST PROCEDURES

Intermittent Simulation

To reproduce the conditions which create an intermittent fault so that it may be identified during testing, some of the following methods may be used

  1. Applying light vibration to components.
  2. Heating a component.
  3. Wiggling or bending a wiring harness.
  4. Applying humidity to a component.
  5. Remove or apply a vacuum supply source.

Monitor circuit/component voltage or resistance while attempting to simulate intermittent. If vehicle is running, monitor for self-diagnostic codes. Use the results of these tests to identify a faulty component or an area which should be checked closely for the problem.

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