1991 FORD FESTIVA Fuel system

Fuel Pump Circuit
1. Turn ignition on. Connect jumper wire between fuel pump test connector terminals. See Fig. 1 or Fig. 2 . Turn ignition on to activate
fuel pump.
2. Listen for fuel pump sound. If there is no sound, check main fuse, inertia switch (located at left rear shock tower), fuel pump rel ay, fu el
pump and all electrical connections.

Fig. 1: Festiva Fuel System Electrical Schematic

Courtesy of FORD MOTOR CO.
(1)For 1991 fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article. For 1992 fuel pressure specifications,
see FUEL PRESSURE SPECIFICATIONS
article.
Page 2 of 4 MITCHELL 1 ARTICLE - F - BASIC TESTING 1991-92 ENGINE PERFORMANCE Ford Motor Co. Basic Diagnostic Proced
...
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B959286D2%2D3A85%2D4BFC%2D9C5C%2D
...

Fig. 2: Capri Fuel System Electrical Schematic
Courtesy of FORD MOTOR CO.
Fuel Pump Relay
Remove fuel pump relay (located near heater duct under carpet). Apply positive 12 volts to relay terminals "A" and "B" together. See Fig. 3 .
Measure voltage between terminal "C" and ground, while individually grounding terminals "D" and "E". Ensure voltage is as specified. See
FUEL PUMP RELAY SPECIFICATIONS
table. If voltage is not as specified, replace relay.
FUEL PUMP RELAY SPECIFICATIONS

Fig. 3: Identifying Fuel Pump Relay Terminals

Courtesy of FORD MOTOR CO.
IGNITION CHECKS
Firing Order
Inspect spark plug wiring routing. Ensure firing order is 1-3-4-2.
Spark
1. Crank engine. Check for a strong Blue spark at each spark plug wire by using a high output spark tester. Ensure resistance of each spark
plug wire is 4000-6000 ohms per foot.
2. Disconnect and inspect all related ignition system connectors and harness. Clean or repair as necessary, and recheck spark. If st il l n o
spark, go to IGNITION COIL POWER SOURCE
.
Ignition Coil Power Source
Disconnect primary wires at ignition coil. Turn ignition on. Measure voltage between Black/White wire on harness connector and ground. If
voltage is not greater than 10 volts, check battery feed, ignition switch and fusible links. If voltage is greater than 10 volts, go to IGNITION
COIL RESISTANCE .
Ignition Coil Resistance
Measure resistance between primary terminals of coil. Measure resistance between positive primary terminal and coil tower. See IGNITION
COIL RESISTANCE table. Verify resistance between coil case and primary positive terminal is infinite. Replace coil if resistance
measurements are not within specifications.
IGNITION COIL RESISTANCE
IDLE SPEED & IGNITION TIMING
Ensure idle speed and ignition timing are set to specification. For adjustment procedures, see ON-VEHICLE ADJUSTMENTS article.
SUMMARY
If no faults were found while performing BASIC TESTING , proceed to TESTS W/CODES article in the ENGINE PERFORMANCE Section.
If no hard codes are found in self-diagnostics, proceed to TESTS W/O CODES article in the ENGINE PERFORMANCE Section for diagnosis
by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.
Terminal "D"Terminal "E"Terminal "C" Voltage
OpenOpenLess than one
GroundedOpenLess than 10
OpenGroundedGreater than 10
GroundedGroundedGreater than 10
ApplicationPrimary (Ohms)Secondary (Ohms)
1.3L & 1.6L0.8-1.66000-30,000
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Page 3 of 4 MITCHELL 1 ARTICLE - F - BASIC TESTING 1991-92 ENGINE PERFORMANCE Ford Motor Co. Basic Diagnostic Proced
...
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B959286D2%2D3A85%2D4BFC%2D9C5C%2D
...

VANE AIR TEMPERATURE RESISTANCE (1)
WIDE OPEN THROTTLE SWITCH (1.3L)
This switch is part of the throttle position switch. See THROTTLE POSITION SWITCH (1.3L).
MODULES, RELAYS & SOLENOIDS
MODULES
Ignition Module
See IGNITION SYSTEM .
RELAYS
A/C Clutch Relay
See MISCELLANEOUS CONTROLS .
Cooling Fan Relay
See MISCELLANEOUS CONTROLS .
SOLENOIDS
Canister Purge Solenoid
See FUEL EVAPORATION .
Fuel Pressure Regulator Control Solenoid
See FUEL DELIVERY under FUEL SYSTEM.
Idle Speed Control (ISC) Solenoid
This solenoid is part of the Idle Speed Control By-Pass Air (ISC-BPA) valve. See IDLE CONTROL SYSTEM under FUEL SYSTEM.
FUEL SYSTEM
FUEL DELIVERY
Fuel Pressure Regulator
1. Measure fuel pressure. See FUEL PRESSURE in BASIC TESTING article in the ENGINE PERFORMANCE Section. Stop engine.
With fuel pressure tester still installed, measure fuel pressure after 5 minutes. If fuel pressure is greater than 21 psi (1.5 kg/cm
2 ) after 5
minutes, go to step 2). Replace fuel pressure regulator if fuel pressure does not remain higher than 21 psi (1.5 kg/cm
2 ).
2. Remove fuel pressure regulator. Inspect "O" ring, gasket and mounting surfaces for defects. Connect vacuum tester to fuel return tube,
and apply 20 in. Hg vacuum. Replace fuel pressure regulator if vacuum drops by more than 10 in. Hg in 10 seconds. Reinstall fuel
pressure regulator.
3. Again measure fuel pressure. If regulated fuel pressure is higher than specification, check for engine vacuum leaks, damage to fuel
pressure regulator housing or a restricted fuel return line. Replace fuel pressure regulator if no problems are found.
Fuel Pressure Regulator Control Solenoid (1.6L)
1. Locate PRESSURE CONTROL (PRC) solenoid on cowl panel next to canister purge solenoid. Unplug PRC connector. Remove both
vacuum lines. Plug one vacuum port and apply vacuum to remaining port. Replace PRC solenoid if it does not hold vacuum.
2. Connect 12-volt power to PRC terminals. If vacuum drops to zero, PRC solenoid is okay. Replace PRC solenoid if vacuum does not
drop to zero.
FUEL CONTROL
Fuel Injectors
1. Using stethoscope, listen for normal clicking sound at each injector during idle and acceleration. If clicking sound is not heard, remove
electrical connector from injector.
2. Using ohmmeter, measure resistance between injector terminals. See FUEL INJECTOR RESISTANCE
table. Replace injector if
°F (°C)Ohms
-4 (-20)15,000
32 (0)5200
68 (20)2500
104 (40)100
140 (60)600
176 (80)300
(1)Resistance may vary by plus or minus 15 percent
NOTE:For fuel pressure specifications, see FUEL PRESSURE SPECIFICAT IONS
article.
Page 4 of 7 MITCHELL 1 ARTICLE - I - SYSTEM/COMPONENT TESTS 1991 ENGINE PERFORMANCE Ford Motor Co. - Ford/Merc
...
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B7DD6473C%2DB5BB%2D4F20%2D9D70%2D
...

resistance is not within specifications. If injector resistance is okay, check for 12 volts at each injector connector. Repair or replace
connector as necessary.
FUEL INJECTOR RESISTANCE
IDLE CONTROL SYSTEM
Idle Speed Control By-pass Air (ISC-BPA) Valve
1. Remove ISC-BPA valve from engine. Connect a hose from a hot water tap to coolant inlet nipple on ISC-BPA valve. Blow through
valve air port. Note resistance to airflow.
2. Supply hot water at 130°F (56°C) minimum to ISC-BPA valve and allow time for valve to respond. Blow through valve again. If
resistance to airflow does not increase when valve is hot, replace ISC-BPA valve.
3. Apply 12 volts to solenoid terminals. If solenoid does not click, replace ISC-BPA valve.
IGNITION SYSTEM
PICK-UP COIL
Check continuity of pick-up coil. If continuity exists, replace igniter unit. If continuity does not exist, replace pick-up coil.
TIMING CONTROL SYSTEMS
Advance Components (1.3L)
Ignition timing advance is controlled by the ECA.
Advance Components (1.6L Non-Turbo)
Ignition advance is controlled by a centrifugal advance mechanism within the distributor, and by a vacuum advance mechanism. If centrifugal
advance is not within specification, service the distributor. Replace the vacuum advance mechanism if vacuum advance is not within
specification. See IGNITION TIMING
. Also see IGNITION TIMING in ADJUSTMENTS article in the ENGINE PERFORMANCE Section.
IGNITION TIMING
Retard Components (1.6L Turbo)
Positive pressure to the vacuum advance cylinder on the distributor retards ignition timing. The ECA also retards ignition timing when it
receives a signal from a Knock Sensor (KS), Knock Control Unit (KC) and related circuitry.
1. Disconnect and plug hoses at distributor. Connect timing light and start engine. Record ignition timing. Tap intake plenum with plastic
mallet while observing ignition timing. If timing retards, knock control circuitry is okay. If timing does not retard, go to step 2).
2. Unplug KC sensor service connector near ECA. Tap intake plenum with plastic mallet while observing ignition timing. If ignition timing
retards, go to step 3). If timing does not retard, go to step 4).
3. Reconnect KC service connector. Tap intake plenum with plastic mallet while observing ignition timing. If ignition timing retards,
replace knock controller. If ignition timing does not retard, go to step 4).
4. Unplug KC service connector near ECA. Temporarily install a known good KS. Tap intake plenum with plastic mallet while observing
ignition timing. If ignition timing retards, replace KS. If ignition timing does not retard, go to step 5).
5. Turn ignition off. Connect BOB. Ensure VPWR and ground wires to KC are okay. Check all KC wiring for shorts or opens. If wiring is
okay, replace KC.
EMISSION SYSTEMS & SUB-SYSTEMS
FUEL EVAPORATION
Canister Purge Solenoid
1. Disconnect vacuum hoses from solenoid. See Fig. 1 . Blow through port "A". Ensure no air exhausts from port "B".
2. Disconnect 2-wire connector from solenoid. Connect 12 volts to one terminal and ground the other terminal of solenoid. Blow air
though port "A". Ensure air exhausts through port "B".
ApplicationOhms
1.3L & 1.6L12-16
NOTE:For basic ignition checks, see BASIC T EST ING article in the ENGINE PERFORMANCE Section.
ApplicationAuto. Trans.Man. Trans.
1.6L Non-Turbo1-3 @ 8500-4 @ 850
1.6L Turbo10-14 @ 8500-4 @ 850
Page 5 of 7 MITCHELL 1 ARTICLE - I - SYSTEM/COMPONENT TESTS 1991 ENGINE PERFORMANCE Ford Motor Co. - Ford/Merc
...
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B7DD6473C%2DB5BB%2D4F20%2D9D70%2D
...

Fig. 1: Testing Canister Purge Solenoid

Courtesy of FORD MOTOR CO.
Carbon Canister
1. Start and run engine until it is at operating temperature. Stop engine. Remove carbon canister. Carbon canister on 1.3L is located under
brake booster. Carbon canister is located in right side of engine compartment near cowl panel on 1.6L.
2. Inspect carbon canister for presence of liquid fuel, as evidenced by odor or weight. Blow into air vent and ensure air exits fro m fu el
vapor inlet. Replace carbon canister if it contains fuel, or if air does not pass freely through it.
POSITIVE CRANKCASE VENTILATION (PCV)
1. Remove PCV valve from valve cover and disconnect it from PCV h o se . S h a ke va l ve vigo r o u sl y t o e n su r e p l u n ge r is fr e e t o mo ve .
Replace PCV valve if plunger is not free.
2. Idle engine until it is warm. Remove fresh air hose at inlet end. Plug nipple immediately to prevent stalling. Verify presence of vacuum at
inlet end of hose. If vacuum is not present, replace PCV valve or service hoses or loose oil dipstick.
THROTTLE CONTROLS
Dashpot
Disconnect PCV valve. Remove resonance chamber. Push dashpot rod in and then release it. Replace dashpot if rod does not go in slowly and
return quickly.
MISCELLANEOUS CONTROLS
A/C CLUTCH
A/C Clutch Relay
Remove relay from its socket near left headlight, in front of battery. Connect ohmmeter to contact terminals (Blue/Red and Black/White wires
on mating connector). Ohmmeter should indicate continuity. Supply 12 volts to remaining terminals (Green/Yellow and Yellow wires on
mating connector). Ohmmeter should indicate no continuity.
COOLING FAN
Cooling Fan
Unplug connector from cooling fan. Apply 12 volts to one terminal of fan connector. Ground remaining fan connector terminal. Replace fan if
it does not run.
Cooling Fan Control Relay
Remove relay from its socket near left headlight. Connect ohmmeter to contact terminals. Wire colors are Yellow/Red and Black on mating
connector on Festiva; Yellow/Green and Black on Capri. Ohmmeter should indicate continuity. Supply 12 volts to remaining 2 relay
terminals. Ohmmeter should indicate no continuity.
NOTE:Although som e of the controlled devices listed here are not technically engine perform ance
com ponents, they can affect driveability if they m alfunction.
Page 6 of 7 MITCHELL 1 ARTICLE - I - SYSTEM/COMPONENT TESTS 1991 ENGINE PERFORMANCE Ford Motor Co. - Ford/Merc
...
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B7DD6473C%2DB5BB%2D4F20%2D9D70%2D
...

Back To Article
G - T EST S W/CODES
1991-92 ENGINE PERFORMANCE Ford Motor Co. Self-Diagnostics
INTRODUCTION
If no faults were found while performing BASIC TESTING , proceed with self-diagnostics. If no fault codes or only pass codes are present
after entering self-diagnostics, proceed to TESTS W/O CODES article in the ENGINE PERFORMANCE Section for diagnosis by symptom
(i.e., ROUGH IDLE, NO START, etc.).
This article uses many abbreviations for devices, signal names, and wire colors. See SELF
-DIAGNOSTICS ABBREVIATIONS table.
Abbreviations for wire colors used in individual PINPOINT TEST diagrams are as follows:
BLK - Black
BLU - Blue
BRN - Brown
GRN - Green
LT GRN - Light Green
ORG - Orange
PNK - Pink
RED - Red
WHT - White
YEL - Yellow
SELF-DIAGNOSTICS ABBREVIATIONS
SELF-DIAGNOSTIC SYSTEM
Hard Failures
Hard failures cause CHECK ENGINE light (MIL) to come on and remain on until problem is repaired. If MIL comes on and remains on (light
may flash) during vehicle operation, cause of malfunction must be determined using diagnostic (code) charts. If a sensor fails, ECA will use a
substitute value in its calculations to permit continued engine operation. In this condition (limp-in mode), vehicle will run but driveability will
not be optimum.
Intermittent Failures
Intermittent failures may cause MIL to flicker or come on and go off after intermittent defect goes away. Corresponding trouble code, however,
will be retained in ECA memory. If related defect does not reoccur within a certain time frame, related trouble code will be erased from ECA
ApplicationAbbreviation
Analog Volt/OhmmeterVOM
Barometric Pressure SensorBP
Breakout BoxBOB
Canister Purge Control SolenoidCANP
CHECK ENGINE LightMIL
Crankshaft Position SensorCPS
Cylinder Identification SensorCID
Electronic Control AssemblyECA
Electronic Engine ControlEEC
Engine Coolant Temperature SensorECT
Exhaust Gas Oxygen SensorEGO
Idle Speed ControlISC
Ignition Diagnostic MonitorIDM
Keep Alive PowerKAPWR
Key On Engine OffKOEO
Key On Engine RunningKOER
Knock ControlKC
Power & Ground ConnectionsPGC
Fuel Pressure Regulator Control SolenoidPRC
Reference Voltage & Signal ReturnVREF
Self-Test InputSTI
Self-Test OutputSTO
Signal ReturnSIGRTN
Solenoid Controlled By GroundSCG
Switch Monitor LampSML
Switch To GroundSTG
Switch To PowerSTP
Throttle Position SensorTP
Vane Airflow MeterVAF
Vane Air Temperature SensorVAT
Vehicle PowerVPWR
Vehicle Speed SensorVSS
Page 1 of 20 MITCHELL 1 ARTICLE - G - TESTS W/CODES 1991-92 ENGINE PERFORMANCE Ford Motor Co. Self-Diagnostics
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B7DD6473C%2DB5BB%2D4F20%2D9D70%2D
...

Engine control system communicates malfunctions to technician through service codes. These service codes are 2-digit numbers representing a
particular defect. Service codes are transmitted through STO connector.
Service codes are displayed as timed pulses, and may be read with a VOM or Super Star II tester. VOM displays codes by needle sweeps. See
Fig. 2
.
Turn ignition off. Ensure all procedures of EQUIPMENT HOOK
-UP have been followed. Engine should be at normal operating
temperature.

Fig. 2: Reading Service Codes With VOM

Courtesy of FORD MOTOR CO.
VOM
Disconnect and reconnect jumper wire from STI terminal to ground. Turn ignition on. Record displayed codes. Erase codes, and repeat test
procedure to verify all codes are currently valid. See ERASING CODES & RETESTING . Service only those codes which appear during
retest. Refer to TROUBLE CODE DEFINITION
table to find appropriate pinpoint test.
MIL
Turn ignition on. Connect a jumper wire between STI connector and ground. Observe MIL, and record pulses to determine codes stored.
SUPER STAR II Tester
Set center button to TEST position. Turn ignition on. Turn tester on. When activated, tester should display 888 for 2 seconds. Release and
reset center TEST button. After all codes are displayed, release center button. All codes in tester memory may now be reviewed.
ERASING CODES & RETESTING
Erasing codes and retesting will give an indication of whether codes are hard or intermittent defects. Hard codes reset immediately and will be
displayed during retest.
Disconnect negative battery cable. Press brake pedal for 5-10 seconds. Turn off VOM or Super Star II tester. Reconnect battery. Perform tests
under RETRIEVING CODES
to again display and record codes.
TROUBLE CODE DEFINITION
TROUBLE CODE DEFINITION
NOTE:If MIL flashes continuously prior to connecting test equipm ent, go to PINPOINT T EST ST I .
Service CodeFaultCircuit & Pinpoint Test
01Ignition Diagnostic MonitorIDM
02 (1) Crankshaft Position SensorCPS
03 (2) Cylinder Identification SensorCID
06 (2) Vehicle Speed SensorVSS
08Vane Airflow MeterVAF
09Engine Coolant Temperature SensorECT
10Vane Air Temperature SensorVAT
12 (2) Throttle Position SensorTP
14Barometric Pressure SensorBP
15Exhaust Gas Oxygen SensorEGO
17Exhaust Gas Oxygen SensorEGO
25 (2) Fuel Pressure Regulator Control SolenoidPRC
26Canister Purge Control SolenoidCANP
34Idle Speed ControlISC
Codes Not ListedPower & Ground ConnectionsPGC
Page 3 of 20 MITCHELL 1 ARTICLE - G - TESTS W/CODES 1991-92 ENGINE PERFORMANCE Ford Motor Co. Self-Diagnostics
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B7DD6473C%2DB5BB%2D4F20%2D9D70%2D
...

Back To Article
H - T EST S W/O CODES
1991-92 ENGINE PERFORMANCE Ford Motor Co. T rouble Shooting - No Codes
INTRODUCTION
Before diagnosing symptoms or intermittent faults, perform steps in BASIC TESTING and TESTS W/CODES articles in the ENGINE
PERFORMANCE Section. Use this article to diagnose driveability problems existing when a hard fault code is not present or vehicle is not
equipped with a self-diagnostic system.
Symptom checks can direct the technician to malfunctioning component(s) for further diagnosis. A symptom should lead to a specific
component, system test or adjustment.
Use intermittent test procedures to locate driveability problems which DO NOT occur when the vehicle is being tested. These test procedures
should also be used if a soft (intermittent) trouble code was present but no problem was found during self-diagnostic testing.
SYMPTOMS
SYMPTOM DIAGNOSIS
Symptom checks cannot be used properly unless problem occurs while vehicle is being tested. To reduce diagnostic time, ensure steps in
BASIC TESTING and TESTS W/CODES articles in the ENGINE PERFORMANCE Section were performed before diagnosing a symptom.
These symptoms are available for diagnosis.
Backfire through induction or exhaust.
Dieseling (run-on).
Lack of power.
Spark knock (pinging).
Stalls/quits.
Stumble/hesitation during acceleration.
Misses/surges.
Idle is fast/slow return to idle.
Id l e is ro u gh .
Engine speeds up.
Cranks normally/no start.
Cranks normally/slow to start.
Poor fuel economy.
Exhaust smoke/odor.
Fuel odor/leaks.
Fails emission test.
BACKFIRE THROUGH INDUCTION OR EXHAUST
Check vane airflow meter.
Check idle speed control solenoid.
DIESELING (RUN-ON)
Check idle speed control solenoid.
LACK OF POWER
Check vane airflow meter.
Check throttle position switch.
Check heated exhaust gas oxygen sensor.
Check A/C switch.
Check wide open throttle A/C (WAC) relay.
SPARK KNOCK (PINGING)
Verify ignition timing is correct.
Check vane airflow meter.
STALLS/QUITS NOTE:Som e driveability problem s m ay have been corrected by m anufacturer with a revised com puter
calibration chip or com puter control unit. Check with m anufacturer for latest chip or com puter
application.
NOTE:For specific testing procedures, see SYST EM/COMPONENT T EST S article in the ENGINE
PERFORMANCE Section. For specifications, see ADJUST MENT S or SPECIFICAT IONS article in the
ENGINE PERFORMANCE Section.
Page 1 of 3 MITCHELL 1 ARTICLE - H - TESTS W/O CODES 1991-92 ENGINE PERFORMANCE Ford Motor Co. Trouble Shooting -
...
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B7DD6473C%2DB5BB%2D4F20%2D9D70%2D
...