1991 FORD FESTIVA reset

VACUUM PUMP - DIESEL TROUBLE SHOOTING
VACUUM PUMP (DIESEL) TROUBLE SHOOTING CHART
MANUAL TRANSMISSION
MANUAL TRANSMISSION TROUBLE SHOOTING
MANUAL TRANSMISSION/TRANSAXLE TROUBLE SHOOTING
Clogged air bleedsRemove restriction
EGR valve malfunctionReplace EGR valve
Restricted air cleaner filterReplace air filter
Cracked or broken vacuum hosesReplace vacuum hoses
Cracked or broken ignition wiresReplace ignition wires
Vacuum advance malfunctionCheck unit and replace as
necessary
Defective or fouled spark plugsReplace spark plugs
Ping or Spark Knock
Incorrect ignition timingReset ignition timing see
ENGINE PERFORMANCE
Distributor centrifugal or vacuum advance malfunctionCheck operation and replace
as necessary
Carburetor setting too leanReadjust mixture setting, see
ENGINE PERFORMANCE
Vacuum leakEliminate vacuum leak
EGR valve malfunctionReplace EGR valve
Poor Gasoline Mileage
Cracked or broken vacuumReplace vacuum hoses hoses
Vacuum leaksRepair vacuum leaks
Defective ignition wiresReplace wires
Incorrect choke settingReadjust setting, see ENGINE
PERFORMANCE
Defective vacuum advanceReplace vacuum advance
Defective spark plugsReplace spark plugs
Binding carburetor power pistonEliminate binding
Dirt in carburetor jetsClean and/or replace jets
Incorrect float adjustmentReadjust float setting, see
FUEL
Defective power valveReplace power valve, see
ENGINE PERFORMANCE
Incorrect idle speedReadjust idle speed
Engine Stalls
Improper float levelReadjust float level
Leaking needle valve and seatReplace needle valve and seat
Vacuum leaksEliminate vacuum leaks
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:Diesel engines m echanical diagnosis is the sam e as gasoline engines for item s such as noisy valves,
bearings, pistons, etc. T he following trouble shooting covers only item s pertaining to diesel engines.
CONDITION & POSSIBLE CAUSECORRECTION
Excessive Noise
Loose pump-to-drive assembly screwsTighten screws
Loose tube on pump assemblyTighten tube
Valves not functioning properlyReplace valves
Oil Leakage
Loose end plugTighten end plug
Bad seal crimpRemove and re-crimp
seal
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.
ConditionPossible Cause
Noisy In Forward GearsLow gear oil level, Loose bell housing bolts, Worn bearings or
gears
Clunk On Deceleration (FWD Only)Loose engine mounts, Worn inboard CV joints, Worn differential
pinion shaft, Side gear hub counterbore in case worn oversize
Page 25 of 36 MITCHELL 1 ARTICLE - GENERAL INFORMATION Trouble Shooting - Basic Procedures
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GENERAL INFORMATION
T ROUBLE SHOOT ING
* PLEASE READ THIS FIRST *
ENGINE PERFORMANCE
TUNE-UP TROUBLE SHOOTING NOTE:T his article is generic in nature and all inform ation does not apply to all vehicles. For vehicle specific
inform ation, see the appropriate articles in the ENGINE PERFORMANCE category.
NOTE:T his article is generic in nature and all inform ation does not apply to all vehicles. For vehicle specific
inform ation, see the appropriate articles in the ENGINE PERFORMANCE category.
Problem & Possible CauseAction
Carbon Fouled Plugs
C l o gge d Air Fil t e rReplace Air Filter
Incorrect Idle SpeedReset Idle Speed
Faulty Ignition WiringReplace Ignition Wiring
Sticky Valves/Worn Valve SealCheck Valve Train
Fuel Injection OperationCheck Fuel Injection
Wet/Oil Fouled Plugs
Worn Rings/PistonsOverhaul/Replace Engine
Excessive Cylinder WearOverhaul/Replace Engine
Plug Gap Bridged
Combustion Chamber Carbon DepositsClean Combustion
Chamber
Blistered Electrode
Engine OverheatingCheck Cooling System
Loose Spark PlugsClean/Torque Plugs
Over-Advanced TimingReset Timing
Wrong Plug Heat RangeInstall Correct Plug
Melted Electrodes
Incorrect TimingReset Timing
Burned ValvesReplace Valves
Engine OverheatingCheck Cooling System
Wrong Plug Heat RangeInstall Correct Plug
Engine Won't Start
Loose ConnectionsCheck Connections
No PowerCheck Fuses/Battery
Loose/Worn Timing Belt/Chain/GearsCheck Belt/Chain/Gears
Engine Runs Rough
Leaky/Clogged Fuel InjectorsRepair Fuel Injectors
Leaky/Clogged Fuel LinesRepair Fuel Lines
Clogged Fuel FilterReplace Fuel Filter
Incorrect TimingReset Timing/Check
Advance
Faulty Plugs/WiresReplace Plugs/Wires
Uneven CompressionOverhaul/Replace Engine
Poor Acceleration
Incorrect Ignition TimingReset Timing
Leaky ValvesCheck Compression
Component Failure
Spark ArcingReplace Faulty Part
Defective Pick-Up CoilReplace Pick-Up Coil
Defective Ignition CoilReplace Ignition Coil
Defective Control UnitReplace Control Unit
Ignition Diagnosis By Scope Pattern
All Firing Lines Abnormally High
Retarded Ignition TimingReset Ignition Timing
Lean Air/Fuel MixtureAdjust Fuel Mixture
High Secondary ResistanceRepair Secondary
Ign it io n
All Firing Lines Abnormally Low
Rich Air/Fuel MixtureAdjust Air/Fuel Mixture
Arcing Coil WireReplace Coil Wire
Cracked CoilReplace Coil
Low Coil OutputReplace Coil
Low CompressionCheck/Repair Engine
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FUEL INJECTION TROUBLE SHOOTING
Se ve r a l High F ir in g Lin e s
Fuel Mixture UnbalancedCheck Fuel System
EGR Valve Stuck OpenClean/Replace EGR
Valve
High Plug Wire ResistanceReplace Plug Wire
Cracked/Broken PlugsReplace Plugs
Intake Vacuum LeakRepair Leak
Several Low Firing Lines
Fuel Mixture UnbalancedAdjust Fuel Mixture
Plug Wires ArcingReplace Plug Wires
Cracked Coil ArcingReplace Coil
Uneven CompressionCheck/Repair Engine
Faulty Spark PlugsReplace Plugs
Cylinders Not Firing
Cracked Distributor CapReplace Cap
Shorted Plug WiresReplace Plug Wires
Mechanical Engine FaultCheck/Repair Engine
Spark Plugs FouledReplace Plugs
Carbon Track in Distributor CapReplace Cap
Hard Starting
Defective Ignition Coil(s)Replace Coil(s)
Fouled Spark PlugsReplace Plugs
Incorrect TimingReset Ignition Timing
NOTE:T his article is generic in nature and all inform ation does not apply to all vehicles. For vehicle specific
inform ation, see the appropriate articles in the ENGINE PERFORMANCE category.
Problem & Possible CauseAction
Cold Start Valve InoperativeTest Cold Start Valve
Poor Vacuum/Electrical ConnectionRepair Connections
Contaminated FuelTest Fuel for Water/Alcohol
Bad Fuel Pump Relay/CircuitTest Relay/Wiring
Battery Voltage LowCharge/Test Battery
Low Fuel PressureTest Press. Regulator/Pump
No Distributor Reference PulseRepair Ignition System
Coolant Temp. Sensor DefectiveTest Temp. Sensor/Circuit
No Power To InjectorsCheck Injector Fuse/Relay
Hard Starting
Defective Idle Air Control (IAC)Test IAC and Circuit
EGR Valve OpenTest EGR Valve/Control
Circuit
Restricted Fuel LinesInspect/Replace Fuel Lines
Poor MAP Sensor SignalTest MAP Sensor/Circuit
Engine Stalls During Parking ManeuverCheck P.S. Press. Switch
Rough Idle
Dirty Fuel InjectorsClean/Replace Injectors
Poor MAP Sensor SignalTest MAP Sensor/Circuit
Intermittent Fuel Injector OperationCheck Harness Connectors
Erratic Vehicle Speed Sensor InputsHarness Too Close to Plug
Wires
Poor O2 Sensor SignalTest O2 Sensor/Circuit
Faulty PCV SystemCheck PCV Valve and
Hoses
Poor Acceleration
Weak Fuel PumpReplace Fuel Pump
Dirty Fuel InjectorsClean/Replace Injectors
Excessive Intake Valve DepositsClean Intake System
Poor High Speed Operation
Low Fuel Pump VolumeFaulty Fuel Pump/Filter
Poor MAP Sensor SignalTest Speed Sensor/Circuit
Acceleration Ping/Knock
Faulty EGR SystemCheck EGR Valve and
Hoses
Poor Knock Sensor SignalTest Knock Sensor/Circuit
Poor Baro Sensor SignalTest Baro Sensor/Circuit
Improper Ignition TimingAdjust Timing
Engine OverheatingCheck Cooling System
Poor Quality FuelUse Different Fuel
Carbon Build-UpDecarbon Engine
Page 2 of 3 MITCHELL 1 ARTICLE - GENERAL INFORMATION TROUBLE SHOOTING
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carburetor. As the exhaust gas quickly warms the intake mixture, distribution is improved. This results in better cold engine driveability,
shorter choke periods and lower emissions.
Ensure EFE valve in exhaust manifold is not frozen or rusted in a fixed position. On vacuum-actuated EFE system, check EFE thermal vacuu
m
valve and check valve(s). Also check for proper vacuum hose routing. See Fig. 19
.

Fig. 19: Typical Vacuum
-Actuated EFE System
Courtesy of GENERAL MOTORS CORP.
EMISSION MAINTENANCE REMINDER LIGHT (EMR)
If equipped, the EMR light (some models may use a reminder flag) reminds vehicle operator that an emission system maintenance is required.
This indicator is activated after a predetermined time/mileage.
When performing a smog check inspection, ensure EMR indicator is not activated. On models using an EMR light, light should glow when
ignition switch is turned to ON position and should turn off when engine is running.
If an EMR flag is present or an EMR light stays on with engine running, fail vehicle and service or replace applicable emission-related
components. To reset an EMR indicator, refer to appropriate MAINTENANCE REMINDER LIGHTS article in GENERAL INFORMATION.
MALFUNCTION INDICATOR LIGHT (MIL)
The Malfunction Indicator Light (MIL) is used to alert vehicle operator that the computerized engine control system has detected a
malfunction (when it stays on all the time with engine running). On some models, the MIL may also be used to display trouble codes.
As a bulb and system check, malfunction indicator light will glow when ignition switch is turned to ON position and engine is not running.
When engine is started, light should go out.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00130226
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GENERAL INFORMATION
Engine Perform ance Safety Precautions
Always refer to Emission Decal in engine compartment before servicing vehicle. If manual and decal differ, always use decal
specifications.
Do not allow or create a condition of misfire in more than one cylinder for an extended period of time. Damage to converter may occur
due to loading converter with unburned air/fuel mixture.
Always turn ignition off and disconnect negative battery cable BEFORE disconnecting or connecting computer or other electrical
components.
DO NOT drop or shock electrical components such as computer, airflow meter, etc.
DO NOT use fuel system cleaning compounds that are not recommended by the manufacturer. Damage to gaskets, diaphragm materials
and catalytic converter may result.
Before performing a compression test or cranking engine using a remote starter switch, disconnect coil wire from distributor and secure it
to a good engine ground, or disable ignition.
Before disconnecting any fuel system component, ensure fuel system pressure is released.
Use a shop towel to absorb any spilled fuel to prevent fire.
DO NOT create sparks or have an open flame near battery.
If any fuel system components such as hoses or clamps are replaced, ensure they are replaced with components designed for fuel system
use.
Always reassemble throttle body components with new gaskets, "O" rings and seals.
If equipped with an inertia switch, DO NOT reset switch until fuel system has been inspected for leaks.
We a r sa fe t y go ggl e s wh e n d r il l in g o r gr in d in g.
Wear proper clothing which protects against chemicals and other hazards.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00002342
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GENERAL INFORMATION
Parasitic Load Explanation & T est Procedures
* PLEASE READ THIS FIRST *
GENERAL INFORMATION
The term Parasitic Load refers to electrical devices that continue to use or draw current after the ignition switch is turned to OFF position. This
small amount of continuous battery draw is expressed in milliamps (mA). On Chrysler vehicles, a typical Parasitic Load should be no more
than 30 milliamps (0.030 amps). On Ford Motor Co. and General Motors vehicles produced after 1980, a typical Parasitic Load should be no
more than 50 milliamps (0.050 amps).
Vehicles produced since 1980 have memory devices that draw current with ignition off for as long as 20 minutes before shutting down the
Parasitic Drain. When Parasitic Load exceeds normal specifications, the vehicle may exhibit dead battery and no-start condition.
Follow test procedure for checking Parasitic Loads to completion. A brief overview of a suggested test procedure is included along with some
typical Parasitic Load specifications. Refer to GENERAL MOTORS PARASITIC LOAD TABLE chart.
TESTING FOR PARASITIC LOAD
The battery circuit must be opened to connect test switch (shunt) and ammeter into the circuit. When a battery cable is removed, timer circuits
within the vehicle computer are interrupted and immediately begin to discharge. If in doubt about the condition of the ammeter fuse, test it
with an ohmmeter prior to beginning test. An open fuse will show the same reading (00.00) as no parasitic drain. Begin test sequence with the
meter installed and on the 10-amp scale. Select lower scale to read parasitic draw.
CHRYSLER IGNITION OFF DRAW (IOD) TEST
To test for excessive IOD, verify that all electrical accessories are OFF. Turn off all lights, remove ignition key, and close all doors and decklid.
If the vehicle is equipped with electronic accessories (illuminated entry, automatic load leveler, body computer, or high line radio), allow the
system to automatically shut off (time out), up to 3 minutes.
1. Raise the hood and disconnect both battery cables, negative first.
2. Reconnect the negative cable and connect a typical 12-volt test light (low wattage bulb) between the positive cable clamp and the
positive battery post. Remove the engine compartment lamp bulb. If the test light does not light, proceed to step 3
. If the test light does
light, proceed to step, 4
. The test light will indicate IOD greater than 3 amps. After higher amperage IOD has been corrected, proceed to
step 3
.
3. ith 12-volt test light still connected (not lit), connect an ammeter (milliampere scale) between the positive cable clamp and the positive
battery post, disconnect test light, refer to instructions provided with ammeter being used. A reading of 30 milliamperes or less indicates
normal electrical draw. If ammeter reads more than 30 milliamperes, excessive IOD must be corrected.
4. Locate the fuse panel and remove fuses or circuit breakers one at a time, and observe ammeter after each fuse or circuit breaker is
removed. If test light goes out and the reading drops below 30 milliamperes when a certain fuse or circuit breaker is removed, that circuit
may have a defect.
5. If IOD is detected after all fuses and circuit breakers have been removed, disconnect the 60-way connector at the Single Module Engine
Control (SMEC), located outboard of the battery.
6. If excessive IOD is detected after all fused circuits and SMEC have been verified, disconnect the B+ terminal from the alternat o r. If
reading drops below 30 milliamperes, reinstall all fuses and circuit breakers, reconnect B+ terminal at alternator, reconnect battery, and
perform alternator diagnostics.
7. Install engine compartment lamp bulb.
TEST PROCEDURE USING TEST SWITCH
1. Turn ignition off. Remove negative battery terminal cable. Install Disconnect Tool (J-38758) test switch male end to negative battery
cable. Turn test switch knob to OFF position (current through meter). Install negative battery cable to the female end of test switch. NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. For m odel-specific inform ation see appropriate articles where
available.
CAUT ION: Always turn ignition off when connecting or disconnecting battery cables, battery chargers or jum per
cables. DO NOT turn test switch to OFF position (which causes current to run through am m eter or
vehicle electrical system ).
NOTE:Mem ory functions of various accessories m ust be reset after the battery is reconnected.
CAUT ION: IOD greater than 3 am ps m ay dam age m illam pm eter.
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The voltage controlled driver inside the computer operates much like a simple switch because it does not need to worry about limiting current
flow. Recall, this driver typically requires injector circuits with a total leg resistance of 12 or more ohms.
The driver is either ON, closing/completing the circuit (eliminating the voltage-drop), or OFF, opening the circuit (causing a total voltage
drop).
Some manufacturers call it a "saturated switch" driver. This is because when switched ON, the driver allows the magnetic field in the injector
to build to saturation. This is the same "saturation" property that you are familiar with for an ignition coil.
There are two ways "high" resistance can be built into an injector circuit to limit current flow. One method uses an external solenoid resistor
and a low resistance injector, while the other uses a high resistance injector without the solenoid resistor. See the left side of Fig. Fig. 1
.
In terms of injection opening time, the external resistor voltage controlled circuit is somewhat faster than the voltage controlled high resistance
injector circuit. The trend, however, seems to be moving toward use of this latter type of circuit due to its lower cost and reliability. The ECU
can compensate for slower opening times by increasing injector pulse width accordingly.

Fig. 1: Injector Driver Types
- Current and Voltage
CURRENT CONTROLLED CIRCUIT ("PEAK & HOLD")
The current controlled driver inside the computer is more complex than a voltage controlled driver because as the name implies, it has to limit
current flow in addition to its ON-OFF switching function. Recall, this driver typically requires injector circuits with a total leg resistance of
less than 12 ohms.
Once the driver is turned ON, it will not limit current flow until enough time has passed for the injector pintle to open. This period is preset by
the particular manufacturer/system based on the amount of current flow needed to open their injector. This is typically between two and six
amps. Some manufacturers refer to this as the "peak" time, referring to the fact that current flow is allowed to "peak" (to open the injector).
Once the injector pintle is open, the amp flow is considerably reduced for the rest of the pulse duration to protect the injector from
overheating. This is okay because very little amperage is needed to hold the injector open, typically in the area of one amp or less. Some
manufacturers refer to this as the "hold" time, meaning that just enough current is allowed through the circuit to "hold" the already-open
injector open.
There are a couple methods of reducing the current. The most common trims back the available voltage for the circuit, similar to turning down
a light at home with a dimmer.
The other method involves repeatedly cycling the circuit ON-OFF. It does this so fast that the magnetic field never collapses and the pintle
stays open, but the current is still significantly reduced. See the right side of Fig. Fig. 1
for an illustration.
The advantage to the current controlled driver circuit is the short time period from when the driver transistor goes ON to when the injector
actually opens. This is a function of the speed with which current flow reaches its peak due to the low circuit resistance. Also, the injector
closes faster when the driver turns OFF because of the lower holding current.
THE TWO WAYS INJECTOR CIRCUITS ARE WIRED
NOTE:Never apply battery voltage directly across a low resistance injector. T his will cause injector dam age
from solenoid coil overheating.
NOTE:Never apply battery voltage directly across a low resistance injector. T his will cause injector dam age
from solenoid coil overheating.
Page 5 of 19 MITCHELL 1 ARTICLE - GENERAL INFORMATION Waveforms - Injector Pattern Tutorial
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Fig. 9: Hitachi 6
-Cylinder Compressor (5-Cylinder Similar)
Courtesy of NISSAN MOTOR CO., U.S.A.
HITACHI 5 & 6-CYL SHAFT SEAL R & I
Removal
1. Drain oil from suction port, measure oil drained and discard oil. Remove clutch hub, pulley, bearing assembly and coil assembly. See
HITACHI 5 & 6-CYLINDER CLUTCH R & I in this article.
2. Using snap ring pliers, remove retainer ring. Remove key and plug low and high pressure openings of compressor with Plugs
(KV994C4531, KV994C4532 and KV994C4559).
3. Insert Adapter (KV994C1552) into hole in middle of blind cover at low pressure side of compressor. Connect Pressurizer
(KV994C1552) to can of R-12 refrigerant. Wrap a rag around compressor shaft. Apply pressure of 28-71 psi (2-5 kg/cm
2 ) at low
pressure (suction) service valve of compressor. Catch shaft seal seat in rag. See Fig. 11
.
4. Insert shaft seal Remover/Installer (KV994C1143) through the open end of front cover. Depress carbon seal and hook tool at case
projection of shaft seal. Slowly pull out to remove shaft seal. See Fig. 11
.

NOTE:Check com pressor refrigerant oil level when replacing seals. See COMPRESSOR REFRIGERANT OIL
CHECKING article in this section.
NOTE:If shaft seal cannot be pulled out, reset to its original position, and pressurize again.
Page 10 of 18 MITCHELL 1 ARTICLE - A/C COMPRESSOR SERVICING 1991 GENERAL SERVICING Compressor Service
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