Ford Festiva. Manual — part 59
TUNE-UP TROUBLE SHOOTING - GAS ENGINE VEHICLES
BASIC SPARK PLUG TROUBLE SHOOTING CHARTS
Faulty solenoid switch, switch connections or relay
Check all wiring between
relay and solenoid or replace
relay or solenoid as necessary
Broken lead or loose soldered connections
Repair wire or wire
connections as necessary
Solenoid Plunger Vibrates When Switch is Engaged
Weak battery
Charge or replace battery as
necessary
Solenoid contacts corroded
Clean contacts or replace
solenoid
Faulty wiring
Check all wiring leading to
solenoid
Broken connections inside switch cover
Repair connections or replace
solenoid
Open hold-in wire
Replace solenoid
Low Current Draw
Worn brushes or weak
Replace brushes or brush
springs as necessary
High Pitched Whine During Cranking Before Engine Fires but Engine Fires and Cranks Normally
Distance too great between starter pinion and flywheel
Align starter or check that
correct starter and flywheel
are being used
High Pitched Whine After Engine Fires With Key released. Engine Fires and Cranks Normally
Distance too small between starter pinion and flywheel
Flywheel runout contributes
to the intermittent nature
NOTE:
This is GENERAL information. This article is not intended to be specific to any unique situation or
individual vehicle configuration. The purpose of this Trouble Shooting information is to provide a list
of common causes to problem symptoms. For model-specific Trouble Shooting, refer to SUBJECT,
DIAGNOSTIC, or TESTING articles available in the section(s) you are accessing.
CONDITION & POSSIBLE CAUSE
CORRECTION
Normal Spark Plug Condition
Light Tan or Gray deposits
No Action
Electrode not burned or fouled
No Action
Gap tolerance not changed
No Action
Cold Fouling or Carbon Deposits
Overrich air/fuel mixture
Adjust air/fuel mixture, see
ENGINE PERFORMANCE
section
Faulty choke
Replace choke assembly, see
ENGINE PERFORMANCE
section
Clogged air filter
Clean and/or replace air filter
Incorrect idle speed or dirty carburetor
Reset idle speed and/ or clean
carburetor
Faulty ignition wires
Replace ignition wiring
Prolonged operation at idle
Shut engine off during long
idle
Sticking valves or worn valve guide seals
Check valve train
Wet Fouling or Oil Deposits
Worn rings and pistons
Install new rings and pistons
Excessive cylinder wear
Rebore or replace block
Excessive valve guide clearance
Worn or loose bearing
Gap Bridged
Deposits in combustion chamber becoming fused to electrode
Clean combustion chamber of
deposits
Blistered Electrode
Engine overheating
Check cooling system
Wrong type of fuel
Replace with correct fuel
Loose spark plugs
Retighten spark plugs
Over-advanced ignition timing
Reset ignition timing see
ENGINE PERFORMANCE
Pre-Ignition or Melted Electrodes
Incorrect type of fuel
Replace with correct fuel
Incorrect ignition timing
Reset ignition timing see
ENGINE PERFORMANCE
Burned valves
Replace valves
Engine Overheating
Check cooling system
Wrong type of spark plug, too hot
Replace with correct spark
BASIC ELECTRONIC IGNITION TROUBLE SHOOTING CHARTS
BASIC ELECTRONIC IGNITION TROUBLE SHOOTING CHARTS - USING OSCILLOSCOPE PATTERNS
plug, see ENGINE
PERFORMANCE
Chipped Insulators
Severe detonation
Check for over-advanced
timing or combustion
Improper gapping procedure
Re-gap spark plugs
Rust Colored Deposits
Additives in unleaded fuel
Try different fuel brand
Water In Combustion Chamber
Blown head gasket or cracked head
Repair or replace head or head
gasket
NOTE:
Before diagnosing an electronic ignition system, ensure that all wiring is connected properly between
distributor, wiring connector and spark plugs. Ignition problem will show up either as: Engine Will Not
Start or Engine Runs Rough.
CONDITION & POSSIBLE CAUSE
CORRECTION
Engine Won't Start
Open circuit between distributor and bulkhead connector
Repair circuit
Open circuit between bulkhead connector and ignition switch
Repair circuit
Open circuit between ignition switch and starter solenoid
Repair circuit
Engine Runs Rough
Fuel lines leaking or clogged
Tighten fitting, remove
restriction
Initial timing incorrect
Reset ignition timing see
ENGINE PERFORMANCE
Centrifugal advance malfunction
Repair distributor advance
Defective spark plugs or wiring
Replace plugs or plug wiring
Component Failure
Spark arc-over on cap, rotor or coil
Replace cap, rotor or or coil
Defective pick-up coil
Replace pick-up coil
Defective ignition coil
Replace ignition coil
Defective vacuum unit
Replace vacuum unit
Defective control module
Replace control module
CONDITION & POSSIBLE CAUSE
CORRECTION
Firing Voltage Lines are the Same, but Abnormally High
Retarded ignition timing
Reset ignition timing, see
ENGINE PERFORMANCE
section
Fuel mixture too lean
Readjust carburetor, see
ENGINE PERFORMANCE
High resistance in coil wire
Replace coil wire
Corrosion in coil tower terminal
Clean and/or replace coil
Corrosion in distributor coil terminal
Clean and/or replace
distributor cap
Firing Voltage Lines are the Same but Abnormally Low
Fuel mixture too rich
Readjust carburetor, see
ENGINE PERFORMANCE
Breaks in coil wire causing arcing
Replace coil wire
Cracked coil tower causing arcing
Replace coil
Low coil output
Replace coil
Low engine compression
Determine cause and repair
One or More, But Not All Firing Voltage Lines are Higher Than Others
Carburetor idle mixture not balanced
Readjust carburetor, see
ENGINE PERFORMANCE
EGR valve stuck open
Clean and/or replace valve
High resistance in spark plug wires
Replace spark plug wires
Cracked or broken spark plug insulator
Replace spark plugs
Intake vacuum leak
Repair leak
Defective spark plugs
Replace spark plugs
Corroded spark plug terminals
Replace spark plugs
One or More, But Not All Firing Voltage Lines Are Lower Than Others
Curb idle mixture not balanced
Readjust carburetor, see
ENGINE PERFORMANCE
Breaks in plug wires
Replace plug wires causing
arcing
Cracked coil tower causing arcing
Replace coil
Low compression
Determine cause and repair
Defective spark plugs
Replace spark plugs
BASIC DRIVEABILITY PROBLEMS TROUBLE SHOOTING
Corroded spark plugs
Replace spark plugs
Cylinders Not Firing
Cracked distributor cap terminals
Replace distributor cap
Shorted spark plug wire
Determine cause and repair
Mechanical problem in engine
Determine cause and repair
Defective spark plugs
Replace spark plugs
Spark plugs fouled
Replace spark plugs
CONDITION & POSSIBLE CAUSE
CORRECTION
Hard Starting
Binding carburetor linkage
Eliminate binding
Binding choke linkage
Eliminate binding
Binding choke piston
Eliminate binding
Restricted choke vacuum
Check vacuum lines for
blockage
Worn or dirty needle valve and seat
Clean carburetor, see ENGINE
PERFORMANCE
Float sticking
Readjust or replace float see
the ENGINE
PERFORMANCE section
Incorrect choke adjustment
Reset choke adjustment see
ENGINE PERFORMANCE
Defective coil
Replace coil
Improper spark plug gap
Regap spark plugs
Incorrect ignition timing
Reset ignition timing see
ENGINE PERFORMANCE
Detonation
Over-advanced ignition timing
Reset ignition timing see
ENGINE PERFORMANCE
Defective spark plugs
Replace spark plugs
Fuel lines clogged
Clean fuel lines
EGR system malfunction
Check and repair EGR system
PCV system malfunction
Repair PCV system
Vacuum leaks
Check and repair vacuum
system
Loose fan belts
Tighten or replace fan belts,
see ENGINE
PERFORMANCE
Restricted airflow
Remove restriction
Vacuum advance malfunction
Check distributor operation
Dieseling
Binding carburetor linkage
Eliminate binding
Binding throttle linkage
Eliminate blinding
Binding choke linkage or fast idle cam
Eliminate binding
Defective idle solenoid
Replace idle solenoid see
ENGINE PERFORMANCE
Improper base idle speed
Reset idle speed, see see
ENGINE PERFORMANCE
Incorrect ignition timing
Reset ignition timing see
ENGINE PERFORMANCE
Incorrect idle mixture setting
Reset idle mixture, see
ENGINE PERFORMANCE
Faulty Acceleration
Incorrect ignition timing
Reset ignition timing see
ENGINE PERFORMANCE
Engine cold and choke too lean
Adjust choke and allow engine
to warm-up
Defective spark plugs
Replace spark plugs
Defective coil
Replace coil
Faulty Low Speed Operation
Clogged idle transfer slots
Clean idle transfer slots, see
FUEL
Restricted idle air bleeds and passages
Disassemble and clean
carburetor, see FUEL
Clogged air cleaner
Replace air filter
Defective spark plugs
Replace spark plugs
Defective ignition wires
Replace ignition wire see
ENGINE PERFORMANCE
Defective distributor cap
Replace distributor cap
Faulty High Speed Operation
Incorrect ignition timing
Reset ignition timing see
ENGINE PERFORMANCE
Defective distributor centrifugal advance
Replace advance mechanism
Defective distributor vacuum advance
Replace advance unit
Incorrect spark plugs or plug gap
Check gap and/or replace
spark plugs
Faulty choke operation
Check choke and repair as
required
Clogged vacuum passages
Remove restrictions
Improper size or clogged main jet
Check jet size and clean, see
FUEL
Restricted air cleaner
Check filter and replace as
necessary
Defective distributor cap, rotor or coil
Replace cap, rotor or coil
Misfire at All Speeds
Defective spark plugs
Replace spark plugs
Defective spark plug wires
Replace spark plug wires
Defective distributor cap, rotor, or coil
Replace cap, rotor, or coil
Cracked or broken vacuum hoses
Replace vacuum hoses
Vacuum leaks
Repair vacuum leaks
Fuel lines clogged
Remove restriction
Hesitation
Cracked or broken vacuum
Replace vacuum hoses hoses
Vacuum leaks
Repair Vacuum leaks
Binding carburetor linkage
Eliminate binding
Binding throttle linkage
Eliminate binding
Binding choke linkage or fast idle cam
Eliminate binding
Improper float setting
Readjust float setting, see
FUEL
Cracked or broken ignition wires
Replace ignition wires
Rough Idle, Missing or Stalling
Incorrect curb idle or fast idle speed
Reset idle speed, see see
ENGINE PERFORMANCE
Incorrect basic timing
Reset ignition timing see
ENGINE PERFORMANCE
Improper idle mixture adjustment
Reset idle mixture, see
ENGINE PERFORMANCE
Improper feedback system operation
Check feedback system see
ENGINE PERFORMANCE
Incorrect spark plug gap
Reset spark plug gap, see
ENGINE PERFORMANCE
Moisture in ignition components
Dry components
Loose or broken ignition wires
Replace ignition wires
Damaged distributor cap or or rotor
Replace distributor cap or
rotor
Faulty ignition coil
Replace ignition coil
Fuel filter clogged or worn
Replace fuel filter
Damaged idle mixture screw
Replace idle mixture screw,
see FUEL
Improper fast idle cam adjustment
Reset fast idle cam adjustment,
see TUNE- see ENGINE
PERFORMANCE
Improper EGR valve operation
Replace EGR valve
Faulty PCV valve air flow
Replace PCV valve
Choke binding or improper choke setting
Reset choke or eliminate
binding
Vacuum leak
Repair vacuum leak
Improper float bowl fuel level
Reset float adjustment, see
FUEL
Clogged air bleed or idle passages
Clean carburetor passages, see
FUEL
Clogged or worn air cleaner filter
Replace air filter
Faulty choke vacuum diaphragm
Replace diaphragm, see
ENGINE PERFORMANCE
Exhaust manifold heat valve inoperative
Replace heat valve
Improper distributor spark advance
Check distributor operation
Leaking valves or valve components
Check and repair valvetrain
Improper carburetor mounting
Remove and remount
carburetor
Excessive play in distributor shaft
Replace distributor
Loose or corroded wiring connections
Repair or replace as required
Engine Surges
Improper PCV valve airflow
Replace PCV valve
Vacuum leaks
Repair vacuum leaks
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