engine FORD FESTIVA 1991 Service Manual

FUEL DELIVERY SYSTEM
Major components of the fuel delivery system are an electric fuel pump, fuel supply and return lines, a pressure regulator, fuel rail and fuel
injectors. See Fig. 2
or Fig. 3 .

Fig. 2: Locating Fuel Delivery System Components (Festiva)

Courtesy of FORD MOTOR CO.

Fig. 3: Locating Fuel Delivery System Components (Capri)

Courtesy of FORD MOTOR CO.
FUEL PUMP
The fuel pump, located inside the fuel tank, includes a check valve at the outlet and a filter element at the inlet. A pressure relief valve limits
maximu m fu el o u t l et p ressu re.
FUEL PUMP RELAY
This relay prevents fuel pump operation unless the engine is cranking or when a signal from the VAF confirms the engine is running. See Fig.
4 . Internal circuitry holds the relay contacts closed during momentary loss of the VAF signal during rapid deceleration. The fuel pump relay is
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located under the center of the instrument panel, between the panel and the floor.

Fig. 4: Electric Fuel Pump System Schematic

Courtesy of FORD MOTOR CO.
FUEL PRESSURE REGULATOR
The fuel pressure regulator is located at the fuel return end of the fuel rail and maintains fuel pressure within the fuel rail at a constant 36.3 psi
(2.54 kg/cm
2 ) higher than intake manifold pressure.
FUEL PRESSURE REGULATOR CONTROL SOLENOID (PRC) (CAPRI)
This device closes the vacuum supply to the fuel pressure regulator on hot starts, thus increasing fuel pressure within the fuel rail and
preventing fuel percolation which could cause hard starts during hot conditions. The PRC is located on the cowl panel, next to the canister
purge solenoid.
FUEL PUMP SHUT-OFF (INERTIA) SWITCH
The fuel pump shut-off switch is connected in series with the fuel pump and prevents fuel pump operation in the event of major collision or
vehicle rollover. A reset button is provided to reset the switch after it has been triggered. See Fig. 5
.

Fig. 5: Locating Inertia Switch Reset Button

Courtesy of FORD MOTOR CO.
FUEL CONTROL SYSTEM
ELECTRONIC FUEL INJECTION (EFI)
The ECA receives a signal from the CPS (Festiva) or CID (Capri) for basic fuel injector timing. Signals to the ECA from other sensors and
switches affect injector on-time. The amount of fuel injected is determined by the duration of the electronic pulse sent to the fuel injector from
the ECA.
Between idle and 5000 RPM, fuel is supplied by providing one injection per crankshaft rotation (2 injections per cycle) to all cylinders. There
is one injection per 2 crankshaft rotations when engine speed exceeds 5000 RPM. When engine speed exceeds 6400 RPM, fuel injectors are
shut off to prevent engine damage.
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IDLE SPEED
While the engine is cold, the Idle Speed Control By-Pass Air (ISC-BPA) Valve increases idle speed to warm the engine quickly. At engine
temperatures less than 140°F (60°C), the valve is open. As the engine warms, the valve begins to close. The valve is fully closed at engine
temperatures higher than 140°F (60°C). Idle speed is also affected by various switches, sensors and load on the engine.
ELECTRONIC IGNITION SYSTEM
CAPRI
A pick-up coil within the distributor sends a signal to a Distributor-Mounted Ignition Module With Vacuum Advance (DMIVA) within the
distributor. The DMIVA then sends a signal which fires the coil. When the coil fires, the distributor directs high voltage current to the spark
plugs. The DMIVA system operates independently of the ECA.
FESTIVA
A pick-up coil within the distributor sends a signal to a transistorized ignition module on the coil bracket. A timing signal also goes from the
ECA to the ignition module. The ignition module then sends a signal which fires the coil. When the coil fires, the distributor directs high
voltage current to the spark plugs.
IGNITION TIMING CONTROL SYSTEM
CAPRI
Spark timing is controlled by vacuum and centrifugal advance mechanisms and by a signal from the ECA. The ECA does not affect ignition
timing on turbo models. On turbo models, a knock sensor and control unit retard ignition timing when knock occurs.
FESTIVA
The ECA generates a spark timing signal from data received from the BP, CPS and VAF. This signal goes to the ignition module. The ignition
module then sends a signal to fire the coil.
HIGH ALTITUDE SPARK ADVANCE CORRECTION
A barometric pressure sensor is incorporated into the ECA on Festiva and is a separate component on Capri. At high altitudes, the ECA sends
a signal to the ignition module to advance ignition timing. This feature is not used on turbo models.
KNOCK SENSOR (CAPRI)
A Knock Sensor (KS) generates a signal when knock occurs. A control unit processes this signal and then sends it to the ignition module to
retard spark timing. The KS is located in the engine block, near the oil pressure switch. This device is only used on 1.6L turbo engines.
KNOCK CONTROL UNIT (CAPRI)
The Knock Control Unit filters normal engine vibration signals from the KS, then sends a signal to the ignition module to retard spark timing.
This unit, used only on 1.6L turbo engines, is located on right side of engine compartment.
EMISSION SYSTEMS
DECELERATION SYSTEM (DASHPOT)
The deceleration control system closes the throttle plate gradually during deceleration. The dashpot prevents engine stalling on deceleration
and provides a smooth transition from deceleration to sudden acceleration.
EVAPORATIVE SYSTEM
CARBON CANISTER
The carbon canister stores vapors from the fuel tank until they are purged and burned in the engine. On Festiva, carbon canister is
located under the brake booster. On Capri, carbon canister is located on the right side of the engine compartment near the cowl panel.
CANISTER PURGE SOLENOID
This component is connected between the carbon canister and intake manifold. When the ECA sends a signal to the solenoid to open,
fuel vapors in the carbon canister are drawn into the engine.
CANISTER PURGE VALVE
This valve opens to purge vapors from the carbon canister into the engine intake system. The valve is part of the canister purge solenoid.
ROLLOVER VENT VALVE
This valve, located in front of the fuel tank, blocks the vapor line in case of vehicle rollover.
This valve, located in front of the fuel tank, blocks the vapor line in case of vehicle rollover.
CATALYTIC CONVERTER
The catalytic converter is in the exhaust system, between the exhaust manifold and the muffler. It converts certain pollutants in the exhaust
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gases into harmless substances.
PCV VALVE
The Positive Crankcase Ventilation (PCV) valve, located in the valve cover, controls the flow of blow-by gas from the crankcase to the intake
man ifo l d .
SELF-DIAGNOSTIC SYSTEM
The ECA monitors its inputs and outputs. When it detects a malfunction, it sets a code in the ECA and sends a signal to the CHECK ENGINE
warning light. The light remains on until the malfunction is repaired. Trouble codes may be accessed at the Self-Test Output (STO) and Self-
Test Input (STI) connectors, near the battery.
If a sensor fails, the ECA will use a substitute value in its calculations to permit continued engine operation. In this condition, the vehicle will
run, but driveability may be poor. Intermittent failures may result in the CHECK ENGINE warning light flickering or going out after the fault
goes away. The corresponding trouble code, however, will be stored in the ECA. If fault does not recur, the related code will be erased from
ECA memory.
CHECK ENGINE LIGHT
Hard failures cause the CHECK ENGINE warning light to come on and remain on until the malfunction is repaired. If the warning light comes
on and stays on during vehicle operation, determine and correct the cause of the malfunction. NOTE:For additional inform ation and operating procedures for the self-diagnostic system , refer to T EST S
W/CODES article in the ENGINE PERFORMANCE Section.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00022697
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CDI
Capacitor Discharge Ignition
CEC
Computerized Engine Control
CID
Cubic Inch Displacement
cm
Centimeter
CMP
Camshaft Position Sensor
CO
Carbon Monoxide
CO
2
Carbon Dioxide
Cont.
Continued
CONV
Convertible
CP
Canister Purge
CKP
Crankshaft Position Sensor
CTS
Coolant Temperature Sensor
Cu. In.
Cubic Inch
CVC
Constant Vacuum Control
CV
Check Valve or Constant Velocity
CW
Clockwise
CYL or Cyl.
Cylinder
C
3 I
Computer Controlled Coil Ignition
C
4
Computer Controlled Catalytic Converter
"D"
"D"
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EBL
Electronic Back Light
ECM
Engine Control Module
ECT
Engine Coolant Temperature Sensor
EDIS
Electronic Distributorless Ignition System
EEC
Electronic Engine Control
EECS
Evaporative Emission Control System
EEPROM
Electronically Erasable PROM
EFE
Early Fuel Evaporation
EGO
Exhaust Gas Oxygen Sensor
EGR
Exhaust Gas Recirculation
ESA
Electronic Spark Advance
ESC
Electronic Spark Control
EST
Electronic Spark Timing
EVAP
Fuel Evaporative System
EVIC
Electronic Vehicle Information Center
EVP
EGR Valve Position Sensor
Exc.
Except
"F"
° F
Fahrenheit (Degrees)
F/B
Fuse Block
Fed.
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"J"
J/B
Junction Block
"K"
KAPWR
Keep Alive Power
k/ohms
kilo-ohms (1000 ohms)
kg
Kilograms (weight)
kg/cm
2
Kilograms Per Square Centimeter
KM/H
Kilometers Per Hour
KOEO
Key On, Engine Off
KOER
Ke y On , E n gin e R u n n in g
KS
Knock Sensor
kW
Kilowatt
kV
Kilovolt
"L"
L
Liter
lbs. (Lbs. when used in table)
Pounds
LCD
Liquid Crystal Display
L/D
Light Duty
LDP
Leak Detection Pump (Part of EVAP system.)
LED
Light Emitting Diode
LH
Left Hand
"M"
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SBC
Single Bed Converter
SBEC
Single Board Engine Controller
SES
Service Engine Soon
SFI
Sequential (Port) Fuel Injection
SIL
Shift Indicator Light
SIR
Supplemental Inflatable Restraint
SOHC
Single Overhead Cam
SOL or Sol.
Solenoid
SPFI
Sequential Port Fuel Injection
SPK
Spark Control
SPOUT
Spark Output
SRI
Service Reminder Indicator
SRS
Supplemental Restraint System (Air Bag)
STAR
Self-Test Automatic Readout
STO
Self-Test Output
SUB-O
2
Sub Oxygen Sensor
Sw.
Switch
Sys.
System
"T"
TAB
Thermactor Air By-Pass
TAC
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Back To Article
GENERAL INFORMATION
T rouble Shooting - Basic Procedures
* PLEASE READ THIS FIRST *
ACCESSORIES & ELECTRICAL
CHARGING SYSTEM TROUBLE SHOOTING
BASIC CHARGING SYSTEM TROUBLE SHOOTING CHART NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
CONDITION & POSSIBLE CAUSECORRECTION
Vehicle Will Not Start
Dead batteryCheck battery cells, alternator
belt tension and alternator
output
Loose or corroded battery connectionsCheck all charging system
connections
Ignition circuit or switch malfunctionCheck and replace as necessary
Alternator Light Stays On With Engine Running
Loose or worn alternator drive beltCheck alternator drive tension
and condition, See Belt
Adjustment in TUNE-UP article
in the TUNE-UP section
Loose alternator wiring connectionsCheck all charging system
connections
Short in alternator light wiringSee Indicator Warning Lights in
STANDARD INSTRUMENTS
in the ACCESSORIES &
EQUIPMENT section
Defective alternator stator or diodesSee Bench Tests in
ALTERNATOR article
Defective regulatorSee Regulator Check in
ALTERNATOR article
Alternator Light Stays Off With Ignition Switch ON
Blown fuseSee WIRING DIAGRAMS
Defective alternatorSee Testing in ALTERNATOR
article
Defective indicator light bulb or socketSee Indicator Warning Lights in
STANDARD INSTRUMENTS
in the ACCESSORIES &
EQUIPMENT section
Alternator Light Stays OFF With Ignition Switch ON
Short in alternator wiringSee On-Vehicle Tests in
ALTERNATOR article
Defective rectifier bridgeSee Bench Tests in
ALTERNATOR article
Lights or Fuses Burn Out Frequently
Defective alternator wiringSee On-Vehicle Tests in
ALTERNATOR article
Defective regulatorSee Regulator Check in
ALTERNATOR article
Defective batteryCheck and replace as necessary
Ammeter Gauge Shows Discharge
Loose or worn drive beltCheck alternator drive belt
tension and condition. See Belt
Adjustment in TUNE-UP article
in the TUNE-UP section
Defective wiringCheck all wires and wire
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Fig. 2: Ignition Primary Trouble Shooting Chart

STARTER TROUBLE SHOOTING
BASIC STARTER TROUBLE SHOOTING CHART
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
CONDITION & POSSIBLE CAUSECORRECTION
Starter Fails to Operate
Dead battery or bad connections between starter and batteryCheck battery charge and all
wires and connections to
starter
Ignition switch faulty or misadjustedAdjust or replace ignition
switch
Open circuit between starter switch ignition terminal on starter relayCheck and repair wires and
connections as necessary
Starter relay or starter defectiveSee Testing in STARTER
article
Open solenoid pull-in wireTesting in STARTER article
Starter Does Not Operate and Headlights Dim
Weak battery or dead cellCharge or replace battery as
necessary
Loose or corroded battery connectionsCheck that battery connections
are clean and tight
Internal ground in starter windingsSee Testing in STARTER
article
Grounded starter fieldsSee Testing in STARTERS
Armature rubbing on poleSee STARTER article shoes
Starter Turns but Engine Does Not Rotate
Starter clutch slippingSee STARTER article
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