1991 FORD FESTIVA Fuel system

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INST RUMENT PANEL
1991 ACCESSORIES & SAFET Y EQUIPMENT Ford Motor Co. Switches & Instrum ent Panels - Standard
DESCRIPTION & OPERATION
Instrument panel on Capri contains a speedometer, tachometer, fuel, water temperature, oil pressure and voltmeter gauges. A boost gauge is
incorporated into the tachometer on turbo models. Instrument panel is equipped with indicator/warning lights for charging system, air b ag,
manual shift, seat belt, turn signals, high beam and brakes. A CHECK ENGINE light, located on instrument panel, illuminates if a
computerized engine control fault occurs with engine running.
Instrument panel on Festiva contains a speedometer, fuel and water temperature gauges. Instrument panel is equipped with indicator/warning
lights for charging system, oil pressure, seat belt, rear defogger, turn signals, high beam and brakes. A CHECK ENGINE light, located on
instrument panel, illuminates if a computerized engine control fault occurs with engine running.
TROUBLE SHOOTING
FUEL GAUGE
Fuel Gauge Always Reads Empty
If fuel gauge always reads empty, check these items:
Check fuel gauge for open or damaged wires.
Check for open ground at fuel gauge sending unit.
Check for defective fuel sending unit.
Check for defective fuel gauge.
Check for defective instrument panel voltage regulator (Festiva).
Check for blown 10-amp METER fuse in fuse panel.
Check for open in Black/Yellow power feed wire from fuse panel instrument panel.
Check for fuel tank float full of fuel (sunk).
Fuel Gauge Always Reads Full
If fuel gauge always reads full, check these items:
Check for fuel gauge Yellow wire shorted to ground.
Check for defective fuel sending unit.
Check for defective fuel gauge.
Check for defective instrument panel voltage regulator (Festiva).
Fuel Gauge Inaccurate
If fuel gauge is inaccurate, check these items:
Check for faulty (loose or corroded) wire connections.
Check for defective fuel sending unit.
Check for defective instrument panel voltage regulator (Festiva).
TEMPERATURE GAUGE
Temperature Gauge Always Reads Cold
If temperature gauge always reads cold, check these items:
Check temperature gauge for open wire.
Check for defective temperature sender.
Check for defective temperature gauge.
Check for defective instrument panel voltage regulator (Festiva).
Check for blown 10-amp METER fuse in fuse panel.
Check for open in Black/Yellow power feed wire from fuse panel to instrument panel.
Temperature Gauge Always Reads Hot
CAUT ION: On m odels with Supplem ental Restraint System (SRS), observe safety precautions. T he air bag system
is powered directly from the battery and back-up power supply. Before any repairs are perform ed,
disconnect and shield battery ground cable. Disconnect the back-up power supply BEFORE servicing
ANY air bag com ponent. Use caution when working near steering colum n. Air bag could accidentally
deploy at any tim e.
NOTE:Ensure continuity exists between chassis ground and Black wire of instrum ent panel connector,
especially if fault exists in m ultiple gauge circuits. See appropriate chassis wiring diagram in the
WIRING DIAGRAMS Section.
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Turbo Boost Gauge Always Reads High
If turbo boost gauge always reads high, check these items:
Check for damaged White/Black signal wire.
Check for defective boost sensing unit.
Check for defective boost gauge.
Turbo Boost Gauge Inaccurate
If turbo boost gauge is inaccurate, check these items:
Check for loose or corroded connections.
Check for defective boost sensing unit.
Check for defective boost gauge.
TESTING
FUEL GAUGE SENDING UNIT
Capri
Remove rear seat cushion. Disconnect fuel pump/fuel gauge sending unit electrical connector at access cover. Turn ignition on. Fuel gauge
should read empty. Using a jumper wire, connect Yellow fuel gauge wire of vehicle harness connector to ground. Fuel gauge should read full.
If fuel gauge operates as specified, replace fuel gauge sending unit.
Festiva
Remove fuel gauge sending unit from tank. See FUEL SENDING UNIT under REMOVAL & INSTALLATION. Connect an ohmmeter and
check sending unit resistance as indicated in FUEL GAUGE SENDING UNIT RESISTANCE (FESTIVA)
table. Replace sending unit if
resistance is drastically different than specification.
FUEL GAUGE SENDING UNIT RESISTANCE (FESTIVA)
OIL PRESSURE GAUGE (CAPRI)
1. Remove electrical connector from oil pressure sending unit located on right side of engine block. Turn ignition switch on. Oil pressure
gauge should read low. Install a jumper wire between Yellow/Red wire of oil pressure sending unit vehicle harness connector and
ground. Oil pressure gauge should read high.
2. If oil pressure gauge operates as specified, replace sending unit. If gauge does not operate as specified, check instrument panel power
and ground circuits.
OIL PRESSURE WARNING LIGHT (FESTIVA)
Light Stays On With Engine Running
1. Turn ignition on (DO NOT start engine). Disconnect Yellow/Red wire from oil pressure switch connector. Light should go off.
2. If light stays on, repair short in Yellow/Red wire between oil indicator light and oil pressure switch. Reconnect wire to switch. Light
should be on with ignition on. If light does not go off when engine is started, check switch or engine for low oil pressure.
Oil Light Will Not Go On With Ignition On
1. Ground Yellow/Red wire at instrument panel connector. If light goes on, repair Yellow/Red wire between oil pressure switch and
indicator light or replace defective oil pressure switch.
2. If light does not illuminate, check bulb or check instrument panel ground circuit.
TEMPERATURE GAUGE (CAPRI)
1. Remove electrical connector from temperature sending unit located at front of cylinder head. Connect one lead of Gauge System Tester
(021-00055) to connector and other tester lead to ground. Set tester to 18 ohms, turn ignition switch on and observe temperature gauge.
Gauge should read 250°F.
2. Turn tester to 60 ohms. Gauge should read 175°F. Turn tester to 223 ohms. Gauge should read 100°F. If all readings are within twice
the needle width of correct reading, gauge is functioning properly. If readings are not as specified, replace gauge.
TEMPERATURE GAUGE (FESTIVA)
See TROUBLE SHOOTING for possible service areas.
TEMPERATURE SENDING UNIT (CAPRI)
Remove sending unit from engine and place in container of water. Heat water to 176°F (80°C). Measure resistance between sending unit
connector and case. Resistance should be 49.3-57.7 ohms. If resistance is not as specified, replace sending unit. NOTE:Inspect fuel tank for distortion or dam age. If distorted or dam aged, repair or replace tank before testing.
Float PositionOhms
Full Position (Up)Approximately 7
Half-Full Position (Middle)Approximately 33
Empty Position (Down)Approximately 95
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2. Lift access plate and disconnect sending unit wiring. To relieve fuel pressure, start engine and run it until engine stalls. Turn ignition off.
Disconnect and plug fuel lines at sending unit. Remove sending u n it a t t a c h in g sc r e ws. R e mo ve se n d in g u n it . To in st a l l , r e ve r se removal
procedure.
TACHOMETER
Removal & Installation
Remo ve in st ru men t p an el . See INSTRUMENT PANEL under REMOVAL & INSTALLATION. Disassemble panel and remove tachometer.
To install tachometer, reverse removal procedure. On Capri, the tachometer/speedometer/boost gauge assembly must be replaced as an
assembly.
TEMPERATURE GAUGE
Removal & Installation
Remo ve in st ru men t p an el . See INSTRUMENT PANEL under REMOVAL & INSTALLATION. Disassemble panel and remove temperature
gauge. To install gauge, reverse removal procedure. On Capri, the temperature/oil pressure gauge assembly must be replaced as an assembly.
TEMPERATURE SENDING UNIT
Removal
Disconnect sending unit wire, located on side of block below thermostat housing (Festiva) or cylinder head (Capri). Remove radiator cap to
relieve cooling system pressure. Position drain pan below sending unit. Remove temperature sending unit.
Installation
To install, apply Pipe Sealant With Teflon (D8AZ-19554-A) to threads of sending unit. Reverse removal procedure to complete installation.
Fill cooling system to proper level. Start engine and check for coolant leaks at sending unit.
WIRING DIAGRAMS
CAUT ION: T achom eter is calibrated at factory. Rough handling could disturb calibration.
NOTE:Refer to the appropriate WIRING DIAGRAMS article in the WIRING DIAGRAMS section.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00028301
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CATALYTIC CONVERTER
Continued operation of vehicle with a severe malfunction could cause converter to overheat, resulting in possible damage to converter and
ve h ic l e .
Any modification to the exhaust system on turbo models, which reduces exhaust backpressure, will lead to lean fuel mixtures and excessive
spark advance. This could cause serious engine damage.
ELECTROSTATIC DISCHARGE SENSITIVE (ESD) PARTS
ENGINE OIL
FUEL PUMP SHUTOFF SWITCH
This switch stops flow of fuel to engine after a collision. The impact does not have to be great for switch to be triggered. Switch must be reset
after collision. Switch is located under left rear speaker in luggage compartment. Press button to reset switch.
FUEL SYSTEM SERVICE
HALOGEN BULBS
PASSIVE RESTRAINTS
RADIATOR CAP
RADIATOR FAN WARNING:Many solid state electrical com ponents can be dam aged by static electricity (ESD). Som e will display a
warning label, but m any will not. Discharge personal static electricity by touching a m etal ground point
on the vehicle prior to servicing any ESD sensitive com ponent.
CAUT ION: Never use non-detergent or straight m ineral oil.
WARNING:Relieve fuel system pressure prior to servicing any fuel system com ponent (fuel injection m odels).
WARNING:Halogen bulbs contain pressurized gas which m ay explode if overheated. DO NOT touch glass portion
of bulb with bare hands. Eye protection should be worn when handling or working around halogen
bulbs.
CAUT ION: Before operating vehicle, securely fasten passive shoulder restraints to the em ergency release buckles.
T he buckle fits in only one way. Ensure to position it properly.
CAUT ION: Always disconnect the fan m otor when working near the radiator fan. T he fan is tem perature controlled
and could start at any tim e even when the ignition key is in the OFF position. DO NOT loosen or rem ove
radiator cap when cooling system is hot.
WARNING:Keep hands away from radiator fan. Fan is controlled by a therm ostatic switch which m ay com e on or
run for up to 15 m inutes even after engine is turned off.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00058075
Page 3 of 3 MITCHELL 1 ARTICLE - FUSES & CIRCUIT BREAKERS Fuses & Circuit Breakers 1988-93 Festiva
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Autolamp Control RelayHeadlight Systems; Daytime Running Lights
Automatic Shutdown (ASD) RelayEngine Performance; Generators & Regulators
Autostick SwitchEngine Performance
Auxiliary Battery RelayGenerators & Regulators
Back-Up LightsBack-Up Lights; Exterior Lights
Barometric (BARO) Pressure SensorEngine Performance
BatteryPower Distribution
Battery Temperature SensorEngine Performance
Body Control ModuleBody Control Computer; Anti-Theft System; Daytime Running
Lights; Engine Performance; Headlight Systems; Warning Systems
Boost Control SolenoidEngine Performance
Boost SensorEngine Performance
Brake Fluid Level SwitchAnalog Instrument Panels
Brake On/Off (BOO) SwitchCruise Control Systems; Engine Performance; Shift Interlock
Systems
Buzzer ModuleWarning Systems
Camshaft Position (CMP) SensorEngine Performance
Central Control ModuleAnti-Theft System
ClockspringAir Bag Restraint System; Cruise Control Systems; Steering
Column Switches
Clutch Pedal Position SwitchStarters
Clutch Start SwitchStarters
Combination MeterAnalog Instrument Panels
Constant Control Relay Module (CCRM)Engine Performance; Electric Cooling Fans
Convenience CenterPower Distribution; Illumination/Interior Lights
Convertible Top MotorPower Convertible Top
Convertible Top SwitchPower Convertible Top
Crankshaft Position (CKP) SensorEngine Performance
Cruise Control ModuleCruise Control Systems
Cruise Control SwitchCruise Control Systems
Condenser Fan Relay(s)Electric Cooling Fans
Data Link Connector (DLC)Engine Performance
Da yt ime R u n n in g Ligh t s M o d u l eDaytime Running Lights; Exterior Lights
Defogger RelayRear Window Defogger
Diagnostic Energy Reserve Module (DERM)Air Bag Restraint System
Discriminating Sensor (Air Bag)Air Bag Restraint System
DistributorEngine Performance
Door Lock ActuatorsPower Door Locks; Remote Keyless Entry
Door Lock Relay(s)Power Door Locks
Electrochromic MirrorPower Mirrors
Electronic Level Control (ELC) Height SensorElectronic Suspension
Electronic Level Control (ELC) ModuleElectronic Suspension
Engine Coolant Temperature (ECT) Sending UnitAnalog Instrument Panels
Engine Coolant Temperature (ECT) SensorEngine Performance
Engine Control ModuleEngine Performance; Generators & Regulators; Starters
ETACS ECUWarning Systems; Power Windows; Remote Keyless Entry
Evaporative (EVAP) Emissions CanisterEngine Performance
EVAP Canister Purge SolenoidEngine Performance
EVAP Canister Vent SolenoidEngine Performance
Exhaust Gas Recirculation (EGR) ValveEngine Performance
Fuel Tank Vacuum SensorEngine Performance
F o g Ligh t sHeadlight Systems; Daytime Running Lights
F o g Ligh t R e l a yHeadlight Systems; Daytime Running Lights
Fuel Door Release SolenoidPower Fuel Door Release
Fuel Gauge Sending UnitAnalog Instrument Panels
Fuel InjectorsEngine Performance
Fuel PumpEngine Performance
Fuel Pump RelayEngine Performance; Power Distribution
Fuse/Relay BlockPower Distribution
Fusible LinksPower Distribution; Generators & Regulators; Starters
GeneratorGenerators & Regulators; Engine Performance; Power Distribution
Generic Electronic Module (GEM)Body Control Modules; Electronic Suspension
Glow Plug RelayEngine Performance
Glow PlugsEngine Performance
GroundsGround Distribution
Headlight Door ModuleHeadlight Doors
Headlight RelayHeadlight Systems; Daytime Running Lights
HeadlightsHeadlight Systems; Daytime Running Lights
Heated Oxygen Sensor(s) (HO2S)Engine Performance
Heated Windshield Control ModuleHeated Windshields
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Height SensorElectronic Suspension
HornsSteering Column Switches
Horn RelaySteering Column Switches
Idle Air Control (IAC) Motor/ValveEngine Performance
Ignition Coil(s)Engine Performance
Ignition Key Lock CylinderAnti-Theft System
Ignition ModuleEngine Performance
Ignition SwitchPower Distribution; Engine Performance; Generators &
Regulators; Starters
Illuminated Entry ModuleIllumination/Interior Lights
Illumination LightsIllumination/Interior Lights
Impact SensorAir Bag Restraint System
Inertia Fuel Shutoff SwitchEngine Performance
In h ib it Rel ayStarters
Instrument ClusterAnalog Instrument Panels
Intake Air Temperature (IAT) SensorEngine Performance
Interior LightsIllumination/Interior Lights
In t erl o ck Swit chStarters
Junction BlockPower Distribution
Keyless Entry ReceiverRemote Keyless Entry
Key Reminder SwitchStarters
Knock SensorEngine Performance
Lamp Control ModuleExterior Lights
License Plate LampExterior Lights
Lighting Control ModuleLighting Control Modules; Anti-Theft System; Daytime Running
Lights; Headlight Systems
Lower RelayPower Convertible Top
Malfunction Indicator Light (MIL)Engine Performance; Instrument Panels
Manifold Absolute Pressure (MAP) SensorEngine Performance
Mass Airflow (MAF) SensorEngine Performance
Mega FuseGenerators & Regulators
Memory Seat/Mirror ModuleMemory Systems
M ir r o r De fo gge rRear Window Defogger
Moon Roof MotorPower Moon Roof
Moon Roof RelayPower Moon Roof
Multi-Function Control ModuleWarning Systems
Neutral Safety SwitchStarters
Oil Level SwitchEngine Performance
Oil Pressure Switch/Sending UnitAnalog Instrument Panels; Engine Performance
Overhead ConsoleOverhead Console
Oxygen Sensor(s) (O2S)Engine Performance
Parking Brake SwitchAnalog Instrument Panels
Park LightsExterior Lights
Park/Neutral Position SwitchStarters; Engine Performance; Anti-Theft System; Body Control
Module
Perimeter Lighting Control RelayExterior Lights
Power AmplifierPower Antennas
Power Antenna ModulePower Antennas
Power Antenna MotorPower Antennas
Power Distribution CenterPower Distribution; Generators & Regulators; Starters
Power Door Lock MotorsPower Door Locks
Power Mirror MotorsPower Mirrors; Memory Systems
Power Sliding Door ControllerPower Sliding Side Door
Power Seat MotorsPower Seats; Memory Systems
Power Steering Pressure SwitchEngine Performance
Power Top MotorPower Convertible Top
Power Top Relay(s)Power Convertible Top
Powertrain Control ModuleEngine Performance; Analog Instrument Panels; Cruise Control
Systems; Data Link Connectors; Generators & Regulators; Starters
Power Window MotorsPower Windows
Power Window Relay(s)Power Windows
Radiator Fan Motor(s)Electric Cooling Fans
Radiator Fan Relay(s)Engine Performance; Electric Cooling Fans;
Rainsense ModuleWiper/Washer Systems
Raise RelayPower Convertible Top
Remote Anti-Theft Personality (RAP) ModuleAnti-Theft System; Starters; Warning Systems
Seat Belt PretensionersAir Bag Restraint System
Seat Belt Retractor SolenoidPassive Restraints
Seat Belt SwitchAir Bag Restraint System; Passive Restraints
Shift Interlock SolenoidShift Interlock Systems
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Shift Lock ActuatorShift Interlock Systems
Side Marker LightsExterior Lights
SIR Coil Assembly (Clockspring)Air Bag Restraint System
Slip Ring (Clockspring)Air Bag Restraint System; Steering Column Switches
SRS Control ModuleAir Bag Restraint System
Starter MotorStarters
Starter Interrupt RelayStarters
Starter SolenoidStarters
Starter RelayStarters
Steering Wheel Position SensorAnti-Lock Brakes
StoplightsExterior Lights
Stoplight SwitchEngine Performance; Cruise Control Systems; Anti-Lock Brakes
Sun Roof ECUPower Sun Roof
Sun Roof MotorPower Sun Roof
Sun Roof Position SensorPower Sun Roof
TaillightsExterior Lights
Throttle Position (TP) SensorEngine Performance
Torque Converter Clutch Solenoid/SwitchEngine Performance
Traction Control SwitchAnti-Lock Brakes
Trailer Tow ConnectorExterior Lights
Trailer Tow RelayExterior Lights
Transmission/TransaxleEngine Performance
Transmission Control Module (TCM)Engine Performance; Starters
Transmission Range SensorStarters; Back-Up Lights; Engine Performance
Transmission Range SwitchBack-Up Lights; Engine Performance; Anti-Theft System
Turn Signal FlasherExterior Lights
Tu r n S ign a l Ligh t sExterior Lights
Twilight Sentinel SwitchHeadlight Systems; Daytime Running Lights
Vapor Canister Leak Detection PumpEngine Performance
Vehicle Control Module (VCM)Engine Performance
Vehicle Dynamic ModuleElectronic Suspension
Vehicle Speed Control ServoCruise Control Systems
Vehicle Speed SensorData Link Connectors; Analog Instrument Panels; Cruise Control
Systems; Electronic Suspension
Voltage RegulatorGenerators & Regulators
Water-In-Fuel SensorEngine Performance; Analog Instrument Panels
Wheel Speed SensorsAnti-Lock Brakes
Window Timer ModulePower Convertible Top
Windshield Intermittent Wiper RelayWiper/Washer Systems
Windshield Washer MotorWiper/Washer Systems
Wiper MotorWiper/Washer Systems
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00130983
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Fig. 2: Computer Engine Control, Fuel Pump System (Grid 4
-7)
Page 3 of 6 MITCHELL 1 ARTICLE - WIRING DIAGRAMS 1991 WIRING DIAGRAMS Ford Motor Co.
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