fuel filter FORD FESTIVA 1991 Service Manual

levels to proper level.
Removal (1.6L & 1.6L Turbo)
1. Relieve fuel pressure and discharge air conditioning system (if equipped). See FUEL PRESSURE RELEASE under REMOVAL &
INSTALLATION. Disconnect and remove battery, battery tray and battery tray support bracket.
2. Release wiring harness retaining straps from battery support tray. Disconnect windshield washer supply hose between fluid reservoir and
hood. Mark hinge locations and remove hood.
3. Disconnect intake air tube and wiring to ignition coil and vane airflow meter. Remove air cleaner/vane airflow meter assembly. Remove
air cleaner assembly support brackets. Disconnect intercooler hoses from turbocharger (if equipped).
4. Drain engine coolant and remove radiator. Disconnect accelerator cable, and remove retaining bracket from cam cover. Position cable to
one side.
5. Disconnect and plug fuel lines at fuel filter and pressure regulator. Disconnect power brake booster manifold vacuum hose from
manifold. Disconnect heater hoses at heater core tubes. Label and remove vacuum hoses located at throttle body.
6. For manual transaxle turbocharged vehicles, disconnect clutch cable and remove support bracket and cable from transmission. On non-
turbo vehicles, disconnect clutch slave hydraulic line. For automatic transaxle, remove transaxle cooler lines.
7. Disconnect starter wiring at starter. Remove harness from locating strap on bracket. Disconnect alternator wiring. Disconnect wiring
from engine coolant sensors located on rear of engine block. Remove ground connection at bracket on thermostat cover. Disconnect O2
sensor wire, main wiring harness connector, TPS connector (turbocharged only), knock sensor connector, distributor wiring and
transaxle wiring. Disconnect ground wire and strap at front of engine, and reinstall lifting eye.
8. Remove engine oil dipstick and retaining clip. Remove power steering pump from mounting bracket. Remove power steering pump
mounting bracket. With hoses attached, position pump aside. Remove upper air conditioning compressor retaining bolts (if equipped).
9. Raise vehicle on hoist. Drain engine oil and cooling system. On vehicles with air conditioning, remove lower air conditioning
compressor mounting bolts, and position compressor out of way.
10. Remove front wheels and tires. Remove front ball joints-to-ste e r in g kn u c kl e s r e t a in in g b o l t s. R e mo ve sp l a sh gu a r d s. Dr a in t ransmission
oil and remove half shafts from differential. Remove front exhaust pipe bracket located on lower side of engine. Disconnect front
exhaust pipe from exhaust manifold, or turbocharger (if equipped).
11. Remove frame support bar-to-engine support bolt. Loosen right control arm bolt and, pivot support bar downward. Disengage rubber
exhaust hangers located directly behind catalytic converter. Allow exhaust system to hang down 6 inches, and support system with
mechanic's wire. Unbolt shift linkage and stabilizer bar at transaxle. Remove nuts from front and rear engine mounts, and lower vehicle.
12. Attach chains onto lift eyes at ends of cylinder head, and support engine with hoist. Remove RH engine mount through bolt. Raise
engine off mounts and slightly pivot engine/transaxle assembly. Disconnect oil pressure sensor and route starter/alternator wiring
harness from engine. Carefully lift engine/transaxle assembly, turn assembly while raising to clear brake master cylinder, shift linkage
universal joint, radiator support and air conditioning lines (if equipped).
13. Remove intake manifold support bracket. Remove gusset plate(s) (if equipped). Remove starter. Remove transaxle-to-engine retaining
bolts. Identify bolts to ensure correct installation. Separate transaxle from engine. On manual transaxle, remove pressure plate, clutch
disc and flywheel. On automatic transaxle, remove flexplate.
Installation (1.6L & 1.6L Turbo)
1. Install transaxle to engine in reverse order of removal. Attach hoist to engine/transaxle assembly and position assembly in vehicle.
Before engine contacts mounts, route starter, alternator and oil pressure sensor wiring, and connect oil pressure sensor. Lower engine
until front mount seats on crossmember. Install through bolt on RH engine mount. DO NOT tighten bolt.
2. Remove hoist. Raise vehicle and support with jackstands. Align rear engine mount to crossmember, and install retaining nuts to front
and rear engine mounts. Tighten nuts to specification. See TORQUE SPECIFICATIONS
table at end of article.
3. On manual transaxles, connect shift coupling and stabilizer. Tighten to specification. On automatic transaxles, connect shift linkage and
oil cooler lines. Tighten linkage retaining bolt, shift cable pivot and oil cooler hose clamps to specification. Connect front exhaust pipe
to manifold (or turbocharger). Install exhaust pipe to support bracket. Tighten bolts to specification. Tighten manifold (or turbocharger)
to specification. Attach rubber exhaust hangers. Position cross brace. Tighten retaining nut and bolt and right control arm front bolt.
4. Install drive axles. Install ball joint retaining bolts and tighten to specification. Mount A/C Compressor to engine (if equipped). Tighten
lower retaining bolts to specification. Install splash guards. Install tire and wheel assemblies. Tighten retaining nuts to specification.
5. Lower vehicle. Install upper A/C compressor retaining bolts (if equipped). Tighten bolts to specification. Tighten RH engine mo u n t
through bolt to specification. Connect alternator wiring.
6. Position power steering pump bracket on stud. Lower pump into engine compartment. Install power steering pump bracket retaining
bolts and nut. Tighten to specification. Install power steering pump and belt. Tighten adjustment nut and pivot bolt to specification.
7. Install engine oil dipstick and retaining clip. Install ground strap and ground wire to cylinder head. Install clutch cable (if equipped).
Connect clutch hydraulic line if equipped with manual transaxle or naturally aspirated. Connect transmission electrical connectors.
Connect fuel lines to fuel filter and pressure regulator. Install intake air tube to throttle body.
8. Install intercooler hoses on turbocharged models. Install air cleaner assembly brackets. Install air cleaner assembly with airflow meter
attached. Install intake air tube. Install coil and airflow meter connectors. Connect coolant crankcase and air bypass hoses. Install
vacuum hoses as noted in disassembly.
9. Connect accelerator cable. Install retaining bracket. Install power brake booster hose. Remove speedometer cable from transaxle. Fill
transaxle to specification. See CAPACITIES in SERVICE & ADJUSTMENT SPECIFICATIONS article. Install speedometer cable.
Connect speedometer cable connector. Fill engine oil to capacity.
10. Install radiator/fan assembly. Tighten bracket retaining bolts to specification. Connect coolant hoses and fan electrical connector. Fill
coolant to specification.
11. Install hood and connect washer hose. Install battery tray support, battery tray, battery and battery hold-down. Connect battery
terminal. Evacuate and charge air conditioning system (if equipped). Road test vehicle and inspect for leaks.
INTAKE MANIFOLD
Removal (1.3L)
CAUT ION: DO NOT allow com pressor to hang by hoses. T ie up com pressor with m echanic's wire.
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Disconnect negative battery cable. Drain cooling system. Remove air cleaner. Remove intake manifold bracket. Disconnect throttle cable.
Mark and disconnect vacuum hoses, fuel hoses and wiring. Remove intake manifold bolts. Remove intake manifold and gasket.
Installation (1.3L)
Clean all gasket mating surfaces. Ensure surface is free of burrs, scratches and cracks. Replace all gaskets. Position gasket and manifold to
cylinder head. Install bolts and tighten to specification. To complete installation, reverse removal procedure.
Removal (1.6L)
1. Disconnect negative battery terminal. Relieve fuel pressure. See FUEL PRESSURE RELEASE under REMOVAL &
INSTALLATION. Drain cooling system. Disconnect intercooler tube and/or air intake tube. Disconnect air by-pass hoses. Disconnect
main engine harness electrical connection and TPS connector. Disconnect vacuum hoses from throttle body.
2. Disconnect fuel lines from fuel filter and pressure regulator. Disconnect throttle cable. Disconnect hoses from By-pass Air Control valve
( B AC ) . R e mo ve B AC va l ve r e t a in in g n u t a n d b o l t . R e mo ve in t a ke manifold retaining nuts and bolts from support bracket and cylinder
head. Remove intake manifold and throttle body assembly.
Installation (1.6L)
1. Install new intake manifold gasket, ensuring coolant passage openings align with openings in cylinder head and manifold. Install intake
manifold. Tighten retaining nut and bolts and support bracket bolts to specification. See TORQUE SPECIFICATIONS
table at end of
article.
2. Install BAC valve and connect air hoses. Connect throttle cable. Connect fuel lines to fuel filters and pressure regulator. Connect main
engine harness connector and TPS connector. Connect vacuum lines to throttle body. Install intake air tube. Connect intercooler tube
and/or intake air tube. Connect air by-pass hoses. Fill cooling system. Connect negative battery terminal. Start engine and check for
fluid leaks and correct operation.
EXHAUST MANIFOLD
Removal (1.3L)
1. Raise vehicle. Remove catalytic converter inlet pipe at exhaust manifold. Remove pulse air tube nuts at inlet pipe. Remove inlet pipe
support bracket bolts. Lower vehicle. Remove air intake duct. Remove exhaust manifold heat shroud bolts and remove shroud.
2. Disconnect oxygen sensor connector. Remove exhaust manifold nuts and remove exhaust manifold. Remove gasket from inlet pipe and
cylinder head.
Installation
Position new gasket on cylinder head and inlet pipe. Install exhaust manifold and nuts. Tighten nuts to specification. See, at end of article,
TORQUE SPECIFICATIONS
table. To complete installation, reverse removal procedure. Tighten all bolts and nuts to specification.
Removal (1.6L Non-Turbo)
Remove intake air tube. Remove front exhaust pipe to exhaust manifold retaining nuts. Remove exhaust support bracket (if equipped). Remove
heat shield. Disconnect O2 sensor electrical connector. Remove exhaust manifold.
Installation (1.6L Non-Turbo)
Install exhaust manifold gaskets. Install heavier gasket first. Install exhaust manifold and tighten retaining nuts to specification. See TORQUE
SPECIFICATIONS table at end of article. Connect O2 sensor electrical connector. Install manifold heat shield. Install intake air tube.
Connect front exhaust pipe to intake manifold and tighten retaining nuts to specification. Install exhaust support bracket, if removed, and
tighten engine mount bolt to specification. Start engine and check for leaks.
Removal (1.6L Turbo)
1. Disconnect negative battery cable. Drain cooling system. Remove throttle body air intake tube. Disconnect intercooler hose from
turbocharger assembly and position both intercooler hoses out of the way. Remove O2 sensor connector from its retaining clip, and
disconnect O2 sensor. Remove lower heat shield and then upper heat shield. Remove turbocharger side heat shield.
2. Remove power steering pump (leave hoses attached) and lay aside. Disconnect lower radiator hose from water pump. Position power
steering pump to access mounting bracket retaining bolts and nut. Remove both bolts and one nut, and remove bracket from engine.
Remove 2 screws retaining air cleaner duct tube, loosen clamp at turbocharger and position duct tube out of the way. Disconnect
coolant return hose at turbocharger. Remove bolt and brass sealing washers from oil supply line at engine block.
3. Raise vehicle. Remove retaining nuts and washers from exhaust pipe flange. Remove 2 bolts retaining exhaust hangers to engine block.
Slide off two rubber exhaust hangers at catalytic converter. Pull exhaust pipe downward and to LH side of vehicle. Disconnect oil return
hose at turbocharger. Disconnect coolant return hose at turbocharger. Remove 2 retaining bolts from turbocharger support bracket.
Remove 2 bolts retaining coolant by-pass tube outlet to water pump. Lower vehicle.
4. Loosen retaining clamp bolt on coolant by-pass tube at rear of cylinder head. Remove 11 retaining nuts from exhaust manifold. Pull
coolant by-pass tube bracket from exhaust stud, and position tube out of way. Grasp manifold, pull off studs and move assembly slightly
to RH side of engine compartment to clear cooling fan, and remove assembly from vehicle.
5. Working on bench, remove 4 nuts retaining turbocharger to exhaust manifold, separate assembly and discard gasket.
Installation (1.6L Turbo)
NOTE:Feed O2 sensor wire and guide through upper heat shield.
NOTE:When reinstalling turbocharger, thoroughly rem ove all gaskets and sealant. Use new gaskets. Add .85
oz. (25 cc) of engine oil in the oil passage of the turbocharger.
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Fig. 1: Installing Cylinder Head Bolts (1.3L)

Courtesy of FORD MOTOR CO.
Removal (1.6L)
1. Release fuel pressure. Drain cooling system. Disconnect negative battery terminal. Remove intake air tube from throttle body.
Disconnect air by-pass hoses. Remove spark plug wires and retainers. Remove intake air tube from air cleaner assembly. Disconnect
coolant hose from thermostat cover. Disconnect vacuum hoses and coolant hoses from throttle body and intake manifold.
2. Disconnect throttle cable and remove retaining brackets and cable. Disconnect fuel lines at fuel filter and pressure regulator. Disconnect
main harness connector. Disconnect O2 sensor connector and remove ground connection retaining screw at bracket. Disconnect
intercooler tubes from turbocharger (if equipped). Remove ground wire and strap retaining bolts at front sides of cylinder head.
3. Remove timing belt covers and timing belt. On turbocharged vehicles, remove exhaust manifold and turbocharger as an assembly. On
non-turbocharged vehicles, disconnect front exhaust pipe from exhaust manifold. Remove intake manifold support upper retaining bolts.
4. Remove cam cover. Remove cylinder head and intake manifold as an assembly. Separate intake manifold from cylinder head (if
required).
Installation (1.6L)
1. Position new (2-piece) exhaust gasket on cylinder head with heavy gasket installed first. Install exhaust manifold to head. Install intake
manifold to head using new gasket. Tighten all manifold nuts to specification. See TORQUE SPECIFICATIONS
table at end of
article.
2. Ensure gasket surfaces of head and block are clean of old gasket and sealant. Place new head gasket on cylinder block. Carefully, place
cylinder head on block. Tighten cylinder head in sequence and in two stages to correct specification. See Fig. 2
.

Fig. 2: Installing Cylinder Head Bolts (1.6L)

Courtesy of FORD MOTOR CO.
3. Install intake manifold support upper retaining bolts and tighten to specification. See TORQUE SPECIFICATIONS
table at end of
NOTE:Ensure coolant passage openings in gasket align with m anifold and cylinder head.
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article. Install timing belt and covers. Install cam cover. On non-turbo engines, connect front exhaust pipe to exhaust manifold. Tighten
nuts to specification.
4. On turbocharged engines, install exhaust manifold and turbocharger assembly. Install ground wire and strap to cylinder head with
retaining bolts. Connect intercooler tubes (if equipped). Connect O2 sensor connector, and install ground wires to bracket on cylinder
head with retaining screw. Connect main engine harness connector. Connect fuel lines to fuel filter and pressure regulator. Install
throttle cable and retaining brackets.
5. Install coolant hoses and vacuum lines to intake manifold and throttle body. Install coolant hose to thermostat cover. Install intake air
tube to air cleaner. Install spark plug wires and retainers. Install intake air tube to throttle body, and connect by-pass hoses. Fill cooling
system. Connect negative battery terminal. Start engine, check for leaks and system operation.
TIMING BELT COVER
Removal & Installation (1.3L)
Remove accessory belts. Remove water pump pulley. Remove crankshaft damper. Remove bolts retaining upper and lower cover halves to
engine front. Remove both covers. To install, reverse removal procedure.
Removal & Installation (1.6L)
Raise vehicle on hoist. Remove RF tire and wheel assembly. Remove RF splash guard. Lower vehicle. Remove spark plugs and set camsh aft
timing to TDC No. 1 cylinder. Remove oil dipstick. Remove water pump pulley. Remove crankshaft pulley, damper and baffle plate. Remove
upper timing belt cover. Remove center and lower timing belt covers. To install, reverse removal procedure.
TIMING BELT
Removal (1.3L)
Remove accessory belts, water pump pulley, crankshaft damper and upper and lower timing belt covers. Mark timing belt direction of rotation
for installation reference. Remove timing belt tensioner pulley bolt. Remove tensioner pulley, spring and spring cover. Remove timing belt.
Installation (1.3L)
1. Ensure timing belt and sprockets are clean and not worn or damaged. Align crankshaft and camshaft timing marks. See Fig. 3 . No. 1
cylinder must be at TDC of compression stroke.
2. Position belt on camshaft sprocket. Install timing belt tensioner spring, spring cover and pulley. Tighten tensioner pulley bolt to
specification. See TORQUE SPECIFICATIONS
table at end of article. To complete installation, reverse removal procedure. Tighten
all bolts and nuts to specification.

Fig. 3: Aligning Camshaft & Crankshaft Timing Marks (1.3L)

Courtesy of FORD MOTOR CO.
Removal (1.6L)
NOTE:Always rotate engine in direction of norm al operation. Rotating crankshaft backwards m ay cause belt to
jump timing.
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ELECTRONIC CONTROL ASSEMBLY (ECA)
REMOVAL & INSTALLATION
Disconnect negative battery cable. On Festiva, from under instrument panel, remove heater duct. On Capri, disengage push-pin retainers by
pulling back on front edges of both center carpet panels. Remove carpet panel retaining screws and panels. Disconnect ECA wire harness
connector. Remove ECA bolts and ECA. To install, reverse removal procedure. On Festiva, ensure mounting clip is inserted into bulkhead
recess.
FUEL SYSTEM
FUEL SYSTEM PRESSURE RELEASE
Remove rear seat assembly. With engine running, disconnect fuel pump connector. Run engine until it stalls to relieve fuel line pressure.
FUEL INJECTORS
Removal
Relieve fuel system pressure. On Capri, remove throttle body. On Festiva, remove intake plenum. See INTAKE PLENUM. Remove fuel inlet
and fuel return line from fuel rail. Remove electrical connectors from injectors. Remove pressure regulator. See Fig. 4
. Remove fuel rail
attaching bolts and fuel rail. Remove fuel injectors.
Installation
Install NEW "O" rings on fuel injectors and lubricate with gasoline. Install fuel injectors into cylinder head. Install fuel rail onto fuel injectors.
Install fuel rail attaching bolts. To complete installation, reverse removal procedure. Check system for leaks.

Fig. 4: Exploded View of Fuel Control System

Courtesy of FORD MOTOR CO.
FUEL PUMP
Removal
Remove fuel tank sending unit. Remove fuel filter from pump. Remove fuel pump wires from sending unit. Remove retaining clamp screw and
clamp. Remove rubber retaining band (if equipped). Remove fuel pump from sending unit.
Installation
To install, reverse removal procedure. Check system for leaks.
INTAKE PLENUM WARNING:ALWAYS relieve fuel pressure before disconnecting any fuel injection-related com ponent. DO NOT
allow fuel to contact engine or electrical com ponents.
WARNING:ALWAYS relieve fuel pressure before disconnecting any fuel-related com ponent. DO NOT allow fuel to
contact engine or electrical com ponents.
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VANE AIRFLOW (VAF) METER
Removal
1. Disconnect negative battery cable. On Capri, disconnect primary and secondary wires from coil. On Festiva, disconnect VAF wire
harness connector. Remove air duct.
2. On Capri, remove retaining bolt and ground wire from air cleaner cover. Remove air cleaner cover bolts and air cleaner cover. From
inside of air cleaner cover, remove VAF meter retaining nuts. On Festiva, remove attaching bolt and 4 nuts. Remove vane airflow met er.
Installation
To install, reverse removal procedure. Position new gasket over VAF mounting studs. Tighten bolts and nuts to specification, see TORQUE
SPECIFICATIONS at end of article.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS NOTE:For all on-vehicle adjustm ents not covered in this article, see ADJUST MENT S article in the ENGINE
PERFORMANCE Section.
ApplicationFt. Lbs. (N.m)
Coolant By-Pass Tube Outlet-To-Water Pump Bolts14-19 (19-26)
Distributor Mounting Bolts14-19 (19-26)
Exhaust Manifold Retaining Nuts29-42 (39-57)
Exhaust Pipe Nuts18-25 (24-34)
Fuel Line-To-Fuel Filter Bolt18-25 (24-34)
Fuel Pressure Regulator Nut(1)
Fuel Rail Retaining Bolt14-19 (19-26)
Heat Shield Bolts14-19 (19-26)
Intake Plenum Bolts/Nuts11-16 (15-22)
Oil Supply Line-To-Turbocharger Bolt12-17 (16-23)
Oxygen Sensor(1)
Power Steering Pump Bracket-To-Engine Bolts/Nut35-48 (47-65)
Throttle Body Bolt/Nuts12-17 (16-23)
Turbocharger Support Bracket Bolts32-45 (43-61)
Turbocharger-To-Exhaust Manifold Nuts20-25 (27-34)
INCH Lbs. (N.m)
Barometric Pressure (BP) Sensor Nut54-84 (6-9)
MAP Sensor Nuts54-84 (6-9)
Oil Supply Line-To-Engine Block Bolt104-156 (12-18)
Vane Airflow Meter Nuts110-152 (12-18)
(1)Information not available from manufacturer.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00022705
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Back To Article
F - BASIC TESTING
1991-92 ENGINE PERFORMANCE Ford Motor Co. Basic Diagnostic Procedures
INTRODUCTION
The following diagnostic steps help prevent overlooking simple problems and begin diagnosis for a no-start condition.
The first step in diagnosing any driveability problem is to verify the complaint. Test drive the vehicle under the conditions in which the
problem reportedly occurred.
Before entering self-diagnostics, perform a careful and complete visual inspection. Most engine control problems result from mechanical
breakdowns, poor electrical connections or damaged/misrouted vacuum hoses. Before condemning the computerized system, perform each test
listed in this article.
PRELIMINARY INSPECTION & ADJUSTMENTS
VISUAL INSPECTION
Perform a visual inspection of all electrical wiring. Look for chafed, stretched, cut or pinched wiring. Ensure electrical connections fit tightly
and are not corroded. Ensure vacuum hoses are properly routed and are not cut or pinched. If necessary, see VACUUM DIAGRAMS article in
the ENGINE PERFORMANCE Section to verify routing and connections. Inspect air induction system for possible vacuum leaks.
MECHANICAL INSPECTION
Compression
Engine mechanical condition can be checked using a compression gauge, vacuum gauge or engine analyzer. See engine analyzer instruction
manual for specific instructions. Lowest compression reading must be not less than 75 percent of highest reading.
Exhaust System Backpressure
Exhaust system can be checked with a vacuum gauge or a 0-5 psi pressure gauge. If a pressure gauge is used, remove O2 sensor. Connect gauge
to O2 sensor port. Start engine, and run at 2500 RPM. If exhaust system backpressure is more than 2 psi, exhaust system or catalytic converter
is plugged.
If a vacuum gauge is used, connect it to intake manifold vacuum. Start engine. Observe vacuum gauge. Open throttle part way and hold steady.
If vacuum gauge drops slowly after stabilizing, check exhaust system for a restriction.
FUEL PRESSURE
Fuel Pressure Release
Start engine (if possible), and unplug VAF meter connector. When engine stalls, turn ignition off and reconnect VAF meter wiring. Usin g sh o p
towel, cover fitting to absorb leakage when opening fuel system.
Fuel Pressure Check
1. Connect fuel pressure gauge between fuel filter and fuel rail. Open main valve, and close drain valve. Locate fuel pump check connector
in engine compartment, near left strut. Connect jumper wire between fuel pump test terminals (Black and Green/White wires on Capri
or Black and Green/Red wires on Festiva).
2. Turn ignition on to activate fuel pump. If pump does not run, check fuel pump circuit. If possible, start engine. Measure and record fuel
pressure. For fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS
article. Disconnect vacuum from pressure
regulator. Turn engine off. Wait 5 minutes and ensure residual pressure is at least 21 psi (1.5 kg/cm
2 ).
3. Operate fuel pump by reconnecting jumper wire at fuel pump check connector. Check fuel pump performance. Pinch hose between
pressure gauge and fuel filter. Do not hold longer than necessary to check pressure.For fuel pressure specifications, see FUEL
PRESSURE SPECIFICATIONS article. If pump does not meet specifications, check fuel pump circuit, fuel pump, fuel tank and fuel
filter or replace fuel pump.
FUEL PUMP PERFORMANCE NOTE:Unless stated otherwise in test procedure, perform all voltage tests with a Digital Volt-Ohm m eter
(DVOM) with a m inim um 10-m egohm input im pedance.
CAUT ION: DO NOT use ignition switch during com pression tests on fuel injected vehicles. Fuel injectors are
triggered by ignition switch during cranking m ode. Use a rem ote starter to crank engine to prevent fire
hazard and catalytic converter and engine oiling system contam ination.
WARNING:ALWAYS relieve fuel pressure before disconnecting any fuel injection system com ponent. DO NOT
allow fuel to contact engine or electrical com ponents.
NOTE:For 1991 fuel pressure specifications, see FUEL PRESSURE SPECIFICAT IONS
article. For 1992 fuel
pressure specifications, see FUEL PRESSURE SPECIFICAT IONS
article.
ApplicationPressure psi (kg/cm2 )Min. Vol. in 10 sec. Ozs. (cc)
Capri(1) 5.5 (167)
Festiva(1) 7.4 (220)
Page 1 of 4 MITCHELL 1 ARTICLE - F - BASIC TESTING 1991-92 ENGINE PERFORMANCE Ford Motor Co. Basic Diagnostic Proced
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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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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
Page 5 of 6 MITCHELL 1 ARTICLE - E - THEORY/OPERATION 1991 ENGINE PERFORMANCE Ford/Mercury Theory & Operation
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Engine overheatingCheck cooling system, See
COOLING
Auto. Trans. pressure regulator valve faultyReplace pressure regulator
va l ve
Auto. Trans. fluid level too lowAdd fluid as necessary
Improper vacuum diverter valve operationReplace vacuum diverter valve
Vacuum leaksInspect vacuum system and
repair as required
Leaking piston ringsReplace piston rings, See
ENGINES
Faulty High Speed Operation
Low fuel pump volumeReplace fuel pump
Le a kin g va l ve s o r wo r nReplace valves and/or springs,
See ENGINES
Incorrect valve timingReset valve timing,See
ENGINES
In t ake man ifo l d rest rict edRemove restriction
Worn distributor shaftReplace distributor
Faulty Acceleration
Improper fuel pump strokeRemove pump and reset pump
stroke
Incorrect ignition timingReset ignition timing, See
TUNE-UP
Le a kin g va l ve sReplace valves, See ENGINES
Worn fuel pump diaphragm or pistonReplace diaphragm or piston
In t ake Backfire
Improper ignition timingReset ignition timing, See
TUNE-UP
Faulty accelerator pump dischargeReplace accelerator pump
Improper choke operationCheck choke and adjust as
required
Defective EGR valveReplace EGR valve
Fuel mixture too leanReset air/fuel mixture, See
TUNE-UP
Choke valve initial clearance too largeReset choke valve initial
clearance
Exhaust Backfire
Vacuum leakInspect and repair vacuum
system
Faulty vacuum diverter valveReplace vacuum diverter valve
Faulty choke operationCheck choke and adjust as
required
Exhaust system leakrepair exhaust system leak
Engine Detonation
Ignition timing too far advancedReset ignition timing, See
TUNE-UP
Faulty ignition systemCheck ignition timing, See
TUNE-UP
Spark plugs loose or faultyRetighten or replace plugs
Fuel delivery system cloggedInspect lines, pump and filter
fo r cl o g
EGR valve inoperativeReplace EGR valve
PCV system inoperativeInspect and/or replace hoses
or valve
Vacuum leaksCheck vacuum system and
repair leaks
Excessive combustion chamber depositsRemove built-up deposits
Leaking, sticking or broken valvesInspect and/or replace valves
External Oil Leakage
Fuel pump improperly seated or worn gasketRemove pump, replace gasket
and seat properly
Oil pan gasket broken or pan bentStraighten pan and replace
ga ske t
Timing chain cover gasket brokenReplace timing chain cover
ga ske t
Rear main oil seal wornReplace rear main oil seal
Oil pan drain plug not seated properlyRemove and reinstall drain
plug
Camshaft bearing drain hole blockedRemove restriction
Oil pressure sending switch leakingRemove and reinstall sending
switch
Excessive Oil Consumption
Worn valve stems or guidesReplace stems or guides, See
Page 10 of 36 MITCHELL 1 ARTICLE - GENERAL INFORMATION Trouble Shooting - Basic Procedures
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