cooling FORD FESTIVA 1991 Repair Manual

TUNE-UP TROUBLE SHOOTING - GAS ENGINE VEHICLES
BASIC SPARK PLUG TROUBLE SHOOTING CHARTS
Faulty solenoid switch, switch connections or relayCheck all wiring between
relay and solenoid or replace
relay or solenoid as necessary
Broken lead or loose soldered connectionsRepair wire or wire
connections as necessary
Solenoid Plunger Vibrates When Switch is Engaged
Weak batteryCharge or replace battery as
necessary
Solenoid contacts corrodedClean contacts or replace
solenoid
Faulty wiringCheck all wiring leading to
solenoid
Broken connections inside switch coverRepair connections or replace
solenoid
Open hold-in wireReplace solenoid
Low Current Draw
Worn brushes or weakReplace brushes or brush
springs as necessary
High Pitched Whine During Cranking Before Engine Fires but Engine Fires and Cranks Normally
Distance too great between starter pinion and flywheelAlign starter or check that
correct starter and flywheel
are being used
High Pitched Whine After Engine Fires With Key released. Engine Fires and Cranks Normally
Distance too small between starter pinion and flywheelFlywheel runout contributes
to the intermittent nature
NOTE:This is GENERAL inform ation. This article is not intended to be specific to any unique situation or
individual vehicle configuration. T he purpose of this T rouble Shooting inform ation is to provide a list
of com m on causes to problem sym ptom s. For m odel-specific T rouble Shooting, refer to SUBJECT ,
DIAGNOST IC, or T EST ING articles available in the section(s) you are accessing.
CONDITION & POSSIBLE CAUSECORRECTION
Normal Spark Plug Condition
Light Tan or Gray depositsNo Action
Electrode not burned or fouledNo Action
Gap tolerance not changedNo Action
Cold Fouling or Carbon Deposits
Overrich air/fuel mixtureAdjust air/fuel mixture, see
ENGINE PERFORMANCE
section
Faulty chokeReplace choke assembly, see
ENGINE PERFORMANCE
section
Clogged air filterClean and/or replace air filter
Incorrect idle speed or dirty carburetorReset idle speed and/ or clean
carburetor
Faulty ignition wiresReplace ignition wiring
Prolonged operation at idleShut engine off during long
idle
Sticking valves or worn valve guide sealsCheck valve train
Wet Fouling or Oil Deposits
Worn rings and pistonsInstall new rings and pistons
Excessive cylinder wearRebore or replace block
Excessive valve guide clearanceWorn or loose bearing
Gap Bridged
Deposits in combustion chamber becoming fused to electrodeClean combustion chamber of
deposits
Blistered Electrode
Engine overheatingCheck cooling system
Wrong type of fuelReplace with correct fuel
Loose spark plugsRetighten spark plugs
Over-advanced ignition timingReset ignition timing see
ENGINE PERFORMANCE
Pre-Ignition or Melted Electrodes
Incorrect type of fuelReplace with correct fuel
Incorrect ignition timingReset ignition timing see
ENGINE PERFORMANCE
Burned valvesReplace valves
Engine OverheatingCheck cooling system
Wrong type of spark plug, too hotReplace with correct spark
Page 21 of 36 MITCHELL 1 ARTICLE - GENERAL INFORMATION Trouble Shooting - Basic Procedures
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B9B990D68%2D660A%2D45E9%2D8F46%2DE
...

Back To Article
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
Page 1 of 3 MITCHELL 1 ARTICLE - GENERAL INFORMATION TROUBLE SHOOTING
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B9B990D68%2D660A%2D45E9%2D8F46%2DE
...

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
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B9B990D68%2D660A%2D45E9%2D8F46%2DE
...

Back To Article
GENERAL INFORMATION
Com puter Relearn Procedures
COMPUTER RELEARN PROCEDURES
Vehicles equipped with engine or transmission computers may require a relearn procedure after vehicle battery is disconnected. Many vehicle
computers memorize and store vehicle operation patterns for optimum driveability and performance. When vehicle battery is disconnected,
this memory is lost. The computer will use default data until new data from each key start is stored. As computer memorizes vehicle operation
for each new key start, driveability is restored. Vehicle computers may memorize vehicles operation patterns for 40 of more key starts.
Customers often complain of driveability problems during relearn stage because vehicle acts differently then before being serviced. Depending
on type and make of vehicle and how it is equipped, the following complaints (driveability problems) may exist:
Harsh Or Poor Shift Quality
Rough Or Unstable Idle
Hesitation Or Stumble
Rich Or Lean Running
Poor Fuel Mileage
These symptoms and complaints should disappear after a number of drive cycles have been memorized. To reduce the possibility of
complaints, after any service which requires battery power to be disconnected, vehicle should be road tested.
GENERIC COMPUTER RELEARN PROCEDURES
Some manufacturers identify a specific relearn procedure which will help establish suitable driveability during relearn stage. These procedures
are especially important if vehicle is equipped with and electronically controlled automatic transmission or transaxle. Always complete
procedure before returning vehicle to customer. The following general procedures are to be used if driveability problems are encountered after
power loss or battery has been disconnected. These procedures may provide an aid in eliminating these problems.
Automatic Transmission
Set parking brake, start engine in "P" or "N" position. Warm-up vehicle to normal operating temperature or until cooling fan cycles.
Allow vehicle to idle for one minute in "N" position. Select "D" and allow engine to idle for one minute.
Accelerate at normal throttle position (20-50%) until vehicle shifts into top gear.
Cruise at light to medium throttle.
Decelerate to a stop, allowing vehicle to downshift, and use brakes normally.
Process may be repeated as necessary.
Manual Transmission
Place transmission in Neutral position.
Ensure emergency brake has been set and all accessories are turned off.
Start engine and bring to normal operating temperature.
Allow vehicle to idle in Neutral for one minute.
Initial relearn is complete, and process will be completed during normal driving.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00012612
Page 1 of 1 MITCHELL 1 ARTICLE - GENERAL INFORMATION Computer Relearn Procedures
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B9B990D68%2D660A%2D45E9%2D8F46%2DE
...

Back To Article
1991 GENERAL SERVICING
A/C Com pressor Refrigerant Oil Checking
ISOLATING COMPRESSOR
1. Connect service gauge set to the compressor service valves and open compressor valves slightly (turn in clockwise). Start engine and
operate air conditioning. Slowly turn compressor suction valve clockwise toward closed (front-seated) position.
2. When suction pressure is reduced to zero or less, turn off engine and compressor and quickly turn suction valve stem in to full front-
seated position. Suction pressure should be slightly above zero. Turn discharge valve into front-seated position.
3. To check oil level, slowly open compressor crankcase plug to relieve any remaining pressure. After oil level is corrected, cap service
gauge ports on both valves. Back-seat suction service valve to allow refrigerant to enter compressor. Open discharge valve halfway.
4. Loosen discharge service valve cap, allowing refrigerant pressure to force air out of compressor. Back-seat service valve and tighten cap.
Compressor is now ready for operation.
REFRIGERANT OIL
Only new, pure, moisture-free refrigerant oil should be used in the air conditioning system. This oil is highly refined and dehydrated to a point
where moisture content is less than 10 parts per million. The oil container must be tightly closed at all times when not in use, or moisture will
be absorbed into the refrigerant oil from the air.
SERVICING PRECAUTIONS
DISCHARGING SYSTEM PRECAUTIONS
If compressor has stem-type service valves, it can be isolated and removed without discharging entire system. See ISOLATING
COMPRESSOR at the beginning of this article. Otherwise, discharge system completely before loosening any fittings.
DISCONNECTING LINES & FITTINGS TEST
After system is discharged, carefully clean area around all fittings to be opened. Always use 2 wrenches when tightening or loosening fittings
to avoid twisting or distorting lines. Cap or plug all openings as soon as lines are removed. DO NOT remove caps until immediately before
connections are made. This will keep entry of air and moisture to a minimum.
CONNECTING LINES AND FITTINGS
A new gasket or "O" ring should be used in all instances when connecting lines or fittings. Dip "O" ring in new refrigerant oil and ensure it is
not twisted during installation. Always use 2 wrenches to prevent damage to lines and fittings.
PLACING SYSTEM IN OPERATION
After component service or replacement has been completed and all connections have been made, evacuate system thoroughly with a vacuum
pump. Charge system with proper amount of refrigerant and perform a leak test. See REFRIGERANT OIL & R-12 SPECIFICATIONS chart in
this section for system capacities. Be sure to check all fittings that have been opened. After system has been leak tested, make a system
performance check.
ATSUGI ROTARY VANE DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at engine idling speed, with controls set for maximum cooling and high
blower speed, for 20 to 30 minutes to return oil to compressor.
2. Stop engine, discharge refrigerant and remove compressor from vehicle. See SERVICING PRECAUTIONS at beginning of article. Drain
compressor oil from compressor discharge port and measure the amount. Oil is sometimes hard to drain when compressor is cool.
Remove oil while compressor is warm.
3. If the amount drained is less than 3 ounces, conduct leak tests at system connections, and if necessary, repair or replace faulty parts.
Check purity of oil and adjust oil level as follows.
4. If amount drained was above 3 ounces, oil level is right. Pour in same amount as was drained. If amount drained was below 3 ounces,
pour in 3 ounces of new refrigerant oil.
BOSCH 6-CYL DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at engine idling speed, with controls set for maximum cooling and high
blower speed, for 20 to 30 minutes to return oil to compressor.
2. Stop engine and discharge refrigerant. Remove refrigerant oil level inspection plug on side of compressor. Oil should be at lower lip of
threaded hole. Add necessary new refrigerant oil (if low). Replace inspection plug and tighten to 10-12 ft. lbs. (14-16 N.m). NOTE:Only com pressors with stem -type service valves can be isolated.
NOTE:Recent findings by the EPA indicate that refrigerant is harm ful to the earth's protective Ozone layer.
When discharging refrigerant, DO NOT allow refrigerant to enter the atm osphere. If available, use
refrigerant recovery/recycle system s when discharging system . Always follow m anufacturer's
instructions.
NOTE:Air conditioning system s will not norm ally need addition of refrigerant oil unless definite oil loss has
occurred due to ruptured lines, leaking com pressor seals, com pressor overhaul or com ponent
replacem ent.
Page 1 of 4 MITCHELL 1 ARTICLE - 1991 GENERAL SERVICING A/C Compressor Refrigerant Oil Checking
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B9B990D68%2D660A%2D45E9%2D8F46%2DE
...

CALSONIC V5 5-CYLINDER
1. Before checking and adjusting oil level, operate compressor at 1000-1500 engine RPM, and set controls at maximum cooling and
blowing speed for 20-30 minutes to return oil to compressor.
2. Stop engine. Discharge refrigerant and remove compressor from vehicle. See SERVICING PRECAUTIONS at the beginning of this
article. Drain compressor oil from compressor discharge port and measure oil amount. Oil may be hard to drain if compressor is cool.
Drain oil while compressor is warm.
3. If amount drained is less than 3.2 ounces, conduct leak tests at system connections. Repair or replace faulty parts as necessary. Check
purity of oil and oil level as follows.
4. If amount drained is more than 3.2 ounces, oil level is okay; fill with same amount drained using new oil. If amount drained is less than
3.2 ounces, pour in 3.2 ounces of new refrigerant oil.
DIESEL KIKI ROTARY VANE DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at engine idling speed, with controls set for maximum cooling and high
blower speed, for 20 to 30 minutes to return oil to compressor.
2. Stop engine, discharge refrigerant and remove compressor from vehicle. See SERVICING PRECAUTIONS at the beginning of this
article. Drain compressor oil from compressor discharge port and measure the amount. Oil is sometimes hard to drain when compressor
is cool. Remove oil while compressor is warm.
3. If the amount is less than 2.4 ounces, conduct leak tests at system connections, and if necessary, repair or replace faulty parts. Check
purity of oil and adjust oil level as follows.
4. If amount drained was above 2.4 ounces, oil level is right. Pour in same amount as was drained. If amount drained was below 2.4
ounces, pour in 2.4 ounces of new refrigerant oil.
DIESEL KIKI 6-CYL DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at engine idling speed, with controls set for maximum cooling and high
blower speed, for 20 to 30 minutes to return oil to compressor.
2. Stop engine, discharge refrigerant and remove compressor from vehicle. See SERVICING PRECAUTIONS at the beginning of this
article. Remove oil drain plug and drain oil. Measure amount of oil drained. Install drain plug with new "O" ring.
3. If amount drained was more than 2 ounces (4.4 ounces for Infinity), refill with same amount of new oil. If amount drained was less than
2 ounces (4.4 ounces for Infinity), refill with 2 ounces (4.4 ounces for Infinity). Install filler plug and recharge system.
FORD FX-15 6-CYLINDER DRAIN & REFILL
1. Slowly discharge system. Remove A/C compressor. Drain compressor oil from suction and discharge ports. Measure amount drained and
discard oil.
2. If amount drained from removed (old) compressor is between 3 and 5 ounces, add drained amount of new SUNINSO 5GS refrigerant oil
into the NEW compressor through suction port.
3. If amount drained is less than 3 ounces, add 3 ounces to the NEW compressor. If amount drained is more than 5 ounces, add 5 ounces.
Use new "O" rings on refrigerant lines. Install A/C compressor. Evacuate and recharge system. Perform leak test.
HARRISON 4-CYL DRAIN & REFILL
The Harrison 4-cyl compressor is charged (new) with 6 ounces of refrigerant oil. Because compressor does not have an oil sump, it should not
have to be removed for oil measurement (it retains very little oil). Note the following situations for checking and adding oil to this compressor.
NO OIL LEAK; REPLACING COMPONENTS
If only the compressor is to be replaced, remove, drain oil, measure and reinstall an equal amount of new oil. If evaporator is being replaced,
add 3 ounces of new oil. If condenser is being replaced, add one ounce.
LOSS OF REFRIGERANT OVER EXTENDED PERIOD
When a loss of refrigerant has occurred over an extended period of time and a component is being replaced to correct the leak, add an
appropriate amount of refrigerant oil to the component.
SIGNS OF EXCESSIVE OIL LEAKAGE
If system has lost excessive oil, remove accumulator. Drain and measure oil. If more than 3 ounces is measured, replace the same amount of
new oil as was drained. If less than 3 ounces is measured, add 3 ounces of new oil. Add and additional 2 ounces of new oil to compensate for
that lost by replacing the accumulator (held in desiccant).
HARRISON V5 5-CYLINDER DRAIN & REFILL
1. If system is operable, run for several minutes to stabilize system before performing repairs. Turn off engine. Discharge system and
remove compressor. See SERVICING PRECAUTIONS at the beginning of this article. Remove drain plug. Drain and measure oil. NOTE:Replacem ent FX-15 com pressors contain 7 ounces of refrigerant oil. Prior to installing com pressor,
drain refrigerant oil and determ ine proper am ount of refrigerant oil to be added.
NOTE:T he Harrison com pressor DOES NOT have an oil sum p. It's crucial that the com pressor rem ains well
oiled. It takes very little tim e to destroy this com pressor if it runs dry.
NOTE:If the exact oil charge is in doubt, drain and flush system . Add a new 6-ounce charge of refrigerant oil to
the system .
Page 2 of 4 MITCHELL 1 ARTICLE - 1991 GENERAL SERVICING A/C Compressor Refrigerant Oil Checking
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B9B990D68%2D660A%2D45E9%2D8F46%2DE
...

2. If more than one ounce is drained, add same amount. If less than one ounce is drained, add 2 ounces of new refrigerant oil to
compressor.
3. If A/C components are replaced, add refrigerant oil to system. Add one ounce if condenser is replaced. Add 3.5 ounces if accumu l at o r is
replaced.
4. When replacing a component which has caused a large refrigerant leak, add 3 ounces of new oil plus the required amount for the part
being replaced. Add oil directly to part being replaced if possible. If oil can not be easily added to part, add oil to accumulator.
HITACHI 5-CYL DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at 1000-1500 engine RPM, and set controls at maximum cooling and high
blowing speed for about 10 minutes to return oil to compressor.
2. Stop engine. Discharge refrigerant and remove compressor from vehicle. See SERVICING PRECAUTIONS at the beginning of this
article. Drain oil from compressor through suction port. Measure amount of oil drained.
3. If amount drained is more than 2.4 ounces, fill with same amount using new oil. If amount drained is less than 2.4 ounces, fill with 2.4
ounces. Install compressor and recharge.
4. If A/C components are replaced. add refrigerant oil to system. Add 1.7 ounces if condenser is replaced. Add 2.4 ounces if evaporator is
replaced. oil does not need to be added if receiver-drier is replaced.
HITACHI 6-CYL DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at engine idling speed, with controls set for maximum cooling and high
blower speed, for 10 minutes to return oil to compressor.
2. Stop engine, discharge refrigerant and remove compressor from vehicle. See SERVICING PRECAUTIONS at the beginning of this
article. Drain oil from compressor suction port. Measure amount of oil drained. If amount drained was more than 2.4 ounces, refill with
same amount of new oil. If amount drained was less than 2.4 ounces, refill with 2.4 ounces. Install compressor and recharge.
MATSUSHITA ROTARY VANE DRAIN & REFILL
Discharge system. Remove compressor from vehicle. Drain oil from compressor through inlet and outlet holes. Refill compressor with 3.4-4.7
ounces of oil through suction port. When replacing evaporator, add 2 ounces. When replacing other A/C components, add 1.4 ounces per
component replaced.
NIPPONDENSO ROTARY VANE DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at engine idle speed, and set controls at maximum cooling and high blowing
speed for 20-30 minutes to return oil to compressor.
2. Stop engine. Discharge refrigerant and remove compressor from vehicle. See SERVICING PRECAUTIONS at the beginning of this
article. Drain compressor oil through compressor intake and discharge ports. Measure amount drained. Oil may be hard to drain if
compressor cool. Drain compressor while compressor is warm.
3. If amount drained is less than 2.4 ounces, conduct leak tests at system connections. If necessary, repair or replace faulty parts. Check
purity of oil level and adjust oil level as follows.
4. If amount drained is more than 2.4 ounces, oil level is okay; fill with same amount drained using new oil. If amount drained is less than
2.4 ounces, pour 2.4 ounces of new refrigerant oil.
5. When replacing condenser, add one ounce. when replacing other A/C components, add .33 ounce per container replaced.
NIPPONDENSO 6 & 10-CYL DRAIN & REFILL
When inspecting system for oil loss, look for signs of leaking (shiny, wet spots on components or underside of hood). If oil leak is noted or
component replacement is required, use the following procedure as indicated:
NO OIL LEAK
Discharge system and change components as necessary. See SERVICING PRECAUTIONS at the beginning of this article. Add refrigerant oil
to components as necessary.
OIL LEAK
1. Slowly discharge system. Repair or replace faulty components. If equipped with a drain plug, remove plug, drain and discard oil. If not
equipped with a drain plug, remove compressor from vehicle and pour oil out suction and discharge ports.
2. Replace drain plug (if equipped). Add 1.5 ounces of new refrigerant oil through suction port. Use new gaskets or "O" rings when
replacing suction and discharge lines.
COMPRESSOR FAILURE OR SYSTEM CONTAMINATED
If either situation exists, discharge system and remove compressor, receiver-drier and expansion valve. Clean expansion valve screen. Flush
entire system. Install new compressor and receiver-drier. New compressors contain correct amount of oil. If installing overhauled compressor,
add 1.5 ounces of new refrigerant oil through suction port.
PANASONIC ROTARY VANE DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at 1000-1500 engine RPM, and set controls at maximum cooling and high
blowing speed for about 10 minutes to return oil to compressor.
2. Stop engine. Discharge refrigerant and remove compressor from vehicle. See SERVICING PRECAUTIONS at the beginning of this NOTE:If oil drained contains m etal chips or other debris, replace receiver-drier. Flush out system before
evacuating and recharging.
Page 3 of 4 MITCHELL 1 ARTICLE - 1991 GENERAL SERVICING A/C Compressor Refrigerant Oil Checking
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B9B990D68%2D660A%2D45E9%2D8F46%2DE
...

article. Drain oil from compressor through suction and discharge ports. Measure amount of oil drained. If amount drained is more than
2.4 ounces, fill with same amount using new oil. If amount drained is less than 2.4 ounces, fill with 2.4 ounces. Install compressor and
recharge.
3. If A/C components are replaced, add refrigerant oil to system. Add 1.4 ounces if condenser is replaced. Add 2 ounces if the evaporator
is replaced. Oil does not need to be added if receiver-drier is replaced.
SANDEN SCROLL DRAIN & REFILL
Discharge system. Remove compressor from vehicle. Drain oil from compressor through inlet and outlet holes. Refill compressor with 2.8
ounces of oil through suction port. When replacing condenser, add .5 ounce. When replacing evaporator, add 1.7 ounces. When replacing
other A/C components, add .5 ounce per component replaced.
SANDEN 5-CYL DRAIN & REFILL
1. Discharge system. Remove compressor belt and loosen mounting bolts. Rotate compressor in brackets until filler plug is at top. Clean
area around filler plug and remove plug slowly. Rotate front hub plate so notch in lobe is 110 degrees from the bottom. This rotates ball
end of top piston to align with oil fill port and allows clearance for dipstick. See Fig. 1
.
2. Insert compressor dipstick diagonally from right to left until stop on dipstick contacts filler plug surface. Remove dipstick and note oil
fill level. Each increment on dipstick represents one ounce of oil. Add oil if necessary to reach 3-4 ounce level.

Fig. 1: Sanden 5
-Cylinder Oil Level Checking
Courtesy of SANDEN INTERNATIONAL U.S.A, INC.
SANDEN 7-CYL DRAIN & REFILL
1. Before checking and adjusting oil level, operate compressor at engine idle speed, and set controls at maximum cooling and high blowing
speed for 20-30 minutes to return oil to compressor.
2. Stop engine. Discharge refrigerant and remove compressor from vehicle. See SERVICING PRECAUTIONS at the beginning of this
article. Remove oil drain plug and drain oil. Measure amount of oil drained. Install drain plug with new "O" ring.
3. If amount drained is more than 3 ounces, fill with same amount using new oil. If amount drained is less than 3 ounces, fill with 3
ounces. Install filler plug. Install compressor and recharge system.
Copyr ight 2009 Mitchell Repair Information Company, LLC. All Rights Reserved.
Article GUID: A00038952
Page 4 of 4 MITCHELL 1 ARTICLE - 1991 GENERAL SERVICING A/C Compressor Refrigerant Oil Checking
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B9B990D68%2D660A%2D45E9%2D8F46%2DE
...

5. Check blower motor fan switch continuity. Resistance should not exceed 4 ohms. See BLOWER MOTOR FAN SWITCH
CONTINUITY table. If continuity is not present, replace fan switch. If continuity is okay, repair open in Black wire from blower motor
switch to ground.
BLOWER MOTOR FAN SWITCH CONTINUITY
REMOVAL & INSTALLATION
CONTROL PANEL
1. Remove bezel screws and accessory bezel. Remove radio. Remove 4 screws securing control panel to instrument panel. Remove glove
box attaching screws and glove box. Remove the retaining clip and disconnect fresh/recirculation air door cable from mode door lever.
2. Disconnect mode select cable at mode control door lever. Disconnect temperature control cable at temperature control mode door lever.
Pull control panel away from instrument panel. Disconnect blower motor switch connector. Disconnect illumination electrical
connector. Remove control panel. To install, reverse removal procedure. Adjust control cables. See ADJUSTMENTS in this article.
BLOWER MOTOR FAN SWITCH
Remove control panel. See CONTROL PANEL R & I
. Remove blower motor fan switch knob. Remove attaching nut. To install, reverse
removal procedure.
HEATER CORE
1. Disconnect negative battery cable. Remove steering wheel by prying out center trim insert and removing steering wheel retaining nut.
Remove 2 steering wheel cover retaining screws and remove cover. Using a steering wheel puller, remove steering wheel.
2. Remove 5 screws and remove lower and upper steering column covers. Disconnect electrical connections and remove multifunction
switch. Remove 5 screws and pull instrument cluster hood rearward. Disconnect electrical connections and remove instrument cluster
hood.
3. Disconnect speedometer cable at transaxle. Remove 4 instrument cluster screws. Pull instrument cluster rearward and disconnect
speedometer cable and electrical connections. Remove instrument cluster.
4. Remove 2 center bracket mounting bolts under steering column and remove bracket. Remove glove box attaching screws and remove
glove box. Remove left and right heater ducts. Remove fuse panel cover. Remove 2 screws securing fuse panel and push fuse panel
inward. DO NOT remove fuse panel.
5. Slide both seats to most forward position. Remove 2 console attaching screws, located in front of seat belt anchors. Slide both seats to
rearmost position. Remove parking brake console insert. Using a Phillips screwdriver, remove push retainer insert, located at front lower
edge of parking brake console. Pull back on parking brake lever and remove parking brake console.
6. Remove gearshift knob. Remove screws and remove shift console. Remove radio/heater control panel bezel screws and remove bezel.
Remove 4 radio attaching screws. Pull radio out and disconnect antenna lead and electrical connections. Disconnect radio ground lead
and remove radio.
7. Remove 4 screws attaching heater control panel. Disconnect control cables and electrical connections. Remove control panel, while
pulling cables through opening.
8. Pry out bolt cover trim inserts in top corners of dash. Remove bolts located under trim panels. Remove 7 instrument panel attaching
bolts and 2 nuts. Pull instrument panel rearward. Disconnect any harness connectors and clips. Remove instrument panel.
9. Disconnect electrical connections at blower and resistor. Remove harness from routing brackets on heater box. Loosen clamp screw
securing air inlet housing. Remove attaching nuts at top and bottom of heater box. Disconnect defroster ducts and remove heater
assembly.
10. Disconnect link connecting 2 defroster doors. Remove attaching screw just above and to right of blower resistor. Turn heater assembly
around and remove screw just to left of blower motor opening. Remove clips securing 2 halves of heater assembly. Separate halves. Lift
out heater core.
11. To install, reverse removal procedure. Ensure all heater control cables are routed and adjusted properly. See ADJUSTMENTS in this
article. Fill cooling system. Check for leaks.
BLOWER MOTOR & RESISTOR
Disconnect negative battery cable. Remove instrument panel spacer brace located below steering column. Remove airflow duct below steering
column. Disconnect blower motor or resistor wiring. Remove 3 blower motor attaching screws or 2 resistor attaching screws and remove
component. To install, reverse removal procedure.
Switch PositionContinuity Between Wire Colors
1Black-to-Blue/White
2Black-to-Blue/Yellow & Blue/Yellow-to-Blue/Red
3Black-to-Blue/Black & Blue/Black-to-Blue/Red
Page 2 of 4 MITCHELL 1 ARTICLE - HEATER SYSTEM 1990-92 HEATER SYSTEMS Ford Motor Co.
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B9B990D68%2D660A%2D45E9%2D8F46%2DE
...

Back To Article
1991 AIR CONDIT IONING & HEAT
MANUAL A/C
A/C SYSTEM SPECIFICATIONS
SPECIFICATIONS
DESCRIPTION
This A/C-heater system is fully integrated to provide cooling, heating and ventilation with either fresh or recirculated air. A/C system is
expansion valve type. Interior air temperature is controlled by cycling the compressor on and off at different rates. A/C compressor is protected
by a low pressure switch, which stops compressor operation when refrigerant pressure is too low. Compressor operation is cut when throttle is
wide open to improve driveability.
The primary system components are compressor, receiver-drier, evaporator, low pressure switch, thermostatic switch, thermostatic expansion
valve, A/C control module, refrigerant lines and air ducts. See Fig. 1
and Fig. 2 . The heater core is continuously supplied with coolant. To
control temperature, air goes through and/or around heater core by way of temperature blend door.

Fig. 1: Identifying A/C System Components

Courtesy of FORD MOTOR CO. CAUT ION: When discharging air conditioning system , use only approved refrigerant recovery/recycling
equipm ent. Make every attem pt to avoid discharging refrigerant into the atm osphere.
ApplicationSpecification
Compressor TypeNippondenso 10-Cylinder
Refrigerant (R-12) Capacity25 ozs.
System Oil Capacity10 ozs.
Compressor Belt Deflection
New9/32-11/32" (8-9 mm)
Used11/32-7/16" (9-11 mm)
System Operating Pressure (1)
Low Side19-25 psi (1.3-1.7 kg/cm2 )
High Side199-220 psi (13.9-15.4
kg/cm
2 )
(1)When measured at 79°F (26°C).
Page 1 of 14 MITCHELL 1 ARTICLE - 1991 AIR CONDITIONING & HEAT MANUAL A/C
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B9B990D68%2D660A%2D45E9%2D8F46%2DE
...