1991 FORD FESTIVA manual transmission

Back To Article
BRAKE SYST EM
1991-92 BRAKES Disc & Drum
DESCRIPTION & OPERATION
On Capri, vehicle braking is provided by front and rear disc brakes. Front and rear brakes are a full-floating, single piston design. The rear
caliper houses a self-adjusting parking brake.
On Festiva, vehicle braking is provided by front disc brakes and rear drum brakes. Rear brakes are a standard non-servo, self-en e r giz in g d e sign .
Front brakes are a full-floating, single piston design with caliper attached to steering knuckle.
BLEEDING BRAKE SYSTEM
BLEEDING PROCEDURES
Manual Bleeding
1. Exhaust vacuum from power brake unit by depressing brake pedal several times. Fill master cylinder with clean brake fluid. Install clear
vinyl bleeder hose onto first bleeder valve to be serviced. See BRAKE LINE BLEEDING SEQUENCE table. Place other end of hose in
clean transparent container.
2. Partially fill container with clean brake fluid. Open the bleeder valve 3/4 turn. Slowly depress brake pedal through its full travel. Close
bleeder valve and release pedal. Pump pedal several times to push air toward wheel cylinders. Repeat procedure until flow of brake
fluid is clear and shows no signs of air bubbles. Proceed to next bleeder valve in sequence and repeat procedure.
BRAKE LINE BLEEDING SEQUENCE
Pressure Bleeding
1. Exhaust vacuum from power brake unit by depressing brake pedal several times. Fill master cylinder with clean brake fluid. With
pressure bleeder at least 1/2 full, connect pressure bleeder to master cylinder using appropriate adaptor.
2. Install clear vinyl bleeder hose onto first bleeder valve to be serviced. See BRAKE LINE BLEEDING SEQUENCE table. Place other
end of hose in clean transparent container. Partially fill container with clean brake fluid. Open bleeder valve 1-2 turns. Allow fluid to
run until flow of fluid is clear and shows no signs of air bubbles. Proceed to next bleeder valve in sequence and repeat procedure.
Remove pressure bleeder and fill master cylinder with clean brake fluid.
ADJUSTMENTS
BRAKE PEDAL HEIGHT (FESTIVA)
1. Block wheels to prevent vehicle from rolling. Start engine and place transmission in Neutral. Fully release parking brake. Move carpet
and insulation away from firewall and brake pedal. Measure distance horizontally between upper center of brake pedal pad and firewall.
Distance should be 8.03-8.23" (204-209 mm).
2. If pedal height is incorrect, inspect pedal assembly for missing, worn or damaged bushings or for loose attaching bolts. Ensure firewall is
not distorted and pedal is not bent. If pedal height is still not within specifications, check brake pedal, booster or master cylinder for
correct and/or correctly installed parts
BRAKE PEDAL FREE PLAY (FESTIVA)
Pump brake pedal several to bleed vacuum from power brake booster. Gently depress brake pedal by hand and measure and measure play
before resistance is felt. Free play should be .16-.28" (4-7 mm). If free play is not within specifications, adjust brake pedal push rod.
BRAKE PEDAL FLOOR CLEARANCE
Capri
1. Move carpet and insulation away from floor board and brake pedal. With engine running and using Brake Pedal Effort Gauge (021-
00001), apply 132 lbs. (59.9 kg) of force to brake pedal. Measure distance from upper surface of brake pedal pad to floor board. If
distance is less than 3.27" (83 mm), inspect pedal assembly for missing, worn or damaged bushings or for loose attaching bolts.
2. Verify that floor board is not distorted and pedal is not bent. If pedal height is still not within specifications, check brake pedal, booster
or master cylinder for correct and/or correctly installed parts. Check for air in hydraulic system.
Festiva
Move carpet and insulation away from floor board and brake pedal. Using Brake Pedal Effort Gauge (021-00001) or equivalent, apply 132
lbs. (59.9 kg) of force to brake pedal. Measure distance from upper surface of brake pedal pad to floor board. If distance is less than 2.68" (68
mm), check for air in hydraulic system, faulty automatic adjusters or excessive shoe clearance.
POWER BRAKE UNIT PUSH ROD
Capri
ApplicationSequence
CapriRR, LF, LR & RF
FestivaRR, LR, RF & LF
NOTE:Check fluid level in m aster cylinder frequently during the bleeding sequence.
Page 1 of 12 MITCHELL 1 ARTICLE - BRAKE SYSTEM 1991-92 BRAKES Disc & Drum
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B7DD6473C%2DB5BB%2D4F20%2D9D70%2D
...

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.
Page 2 of 19 MITCHELL 1 ARTICLE - ENGINE OVERHAUL 1991-92 FORD MOTOR CO. ENGINES 1.3L & 1.6L 4-Cylinder
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B959286D2%2D3A85%2D4BFC%2D9C5C%2D
...

Back To Article
D - ADJUSTMENTS
1991 ENGINE PERFORMANCE Ford/Mercury - On-Vehicle Adjustm ents
ADJUSTMENTS
ENGINE MECHANICAL
Before beginning any on-vehicle adjustments to fuel or ignition systems, ensure engine mechanical condition is okay.
VALVE CLEARANCE
IGNITION TIMING
CAPRI
1. Place automatic transmission in Park or manual transmission in Neutral. Disconnect and plug hoses attached to vacuum diaphragm
assembly on distributor. Connect tachometer and timing light. Turn off all electrical loads.
2. Start engine, and warm it to operating temperature. Ensure idle speed is set to specification, adjusting if necessary. See IDLE SPEED &
MIXTURE . Determine initial timing. See IGNITION TIMING table. If base timing is not correct, loosen distributor mounting bolts
and rotate distributor until marks align. Tighten bolts to 14-18 ft. lbs. (19-25 N.m).
3. Increase engine RPM while observing timing light. Verify ignition timing advances. For Turbo models, go to step 5). For non-Turbo
models, continue with step 4).
4. On non-Turbo models, apply 16 in. Hg vacuum to chamber "A". Verify timing advances by 26-30 degrees. Remove vacuum source from
chamber "A". Apply 8 in. Hg vacuum to chamber "B" while observing timing. Verify timing advances by 3-7 degrees. Stop engine, and
remove test equipment.
5. On Turbo models, apply 20 in. Hg vacuum to advance diaphragm. Verify timing advances by 13-17 degrees. Disconnect vacuum source.
Apply 8 psi (.6 kg/cm
2 ) pressure to advance diaphragm. Verify timing retards by 3-7 degrees. Stop engine, and remove test equipment.
FESTIVA
1. Place manual transmission in Neutral or automatic transmission in Park. Turn all accessories off. Locate one-wire STI (Black) connector
near master cylinder. Using a jumper wire, connect STI terminal to ground. See Fig. 1
. Connect timing light and tachometer.

Fig. 1: Locating Self
-Test Input (STI) Connector
Courtesy of FORD MOTOR CO.
2. Start engine, and warm to operating temperature. Ensure idle speed is set to specification, adjusting if necessary. See IDLE SPEED &
MIXTURE .
3. Check initial timing. White timing mark should align with white mark on crankshaft pulley. If marks do not align, loosen distributor
mounting bolts and rotate distributor until marks align. Tighten bolts to 14-18 ft. lbs. (19-25 N.m).
4. Remove jumper wire. Increase engine RPM, and verify ignition timing advances beyond initial setting. Stop engine, and remove test
equipment.
IGNITION TIMING NOTE:All m odels are equipped with hydraulic lash adjusters. No adjustm ents are required.
Page 1 of 3 MITCHELL 1 ARTICLE - D - ADJUSTMENTS 1991 ENGINE PERFORMANCE Ford/Mercury - On-Vehicle Adjustments
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B959286D2%2D3A85%2D4BFC%2D9C5C%2D
...

IDLE SPEED & MIXTURE
IDLE MIXTURE
IDLE SPEED
1. Turn off all accessories. Place automatic transmission in Park or manual transmission in Neutral. Set parking brake. Connect tachometer
to engine. Warm engine to normal operating temperature. Connect a jumper wire between single-wire STI test connector (Green on
Capri; Black on Festiva) and ground. See Fig. 1
.
2. Locate idle speed control by-pass air (ISC-BPA) valve on intake manifold. Remove cap, and adjust idle speed to specification by turning
idle air adjust screw on ISC-BPA valve. See Fig. 2
. Remove jumper wire.
IDLE RPM

Fig. 2: Locating Idle Air Adjust Screw

Courtesy of FORD MOTOR CO.
THROTTLE POSITION SWITCH (TP)
CAPRI
Throttle position sensor is preset at factory. No adjustment is required.
FESTIVA
1. Ensure idle speed and ignition timing are adjusted to specification. Stop engine. Disconnect negative battery cable.
2. Unplug TP connector at throttle body. Insert appropriate feeler gauge between throttle stop screw and stop lever. Check for continuity
between specified terminals on TP connector. See TP ADJUSTMENT table.
3. To adjust, loosen TP attaching screws. Connect ohmmeter between terminals IDL and TL. See Fig. 3
. Insert a .020" (.5 mm) feeler
gauge between throttle stop screw and stop lever.
4. Rotate TP until ohmmeter indicates continuity. Insert a .028" (.7 mm) thickness gauge between stop screw and stop lever. Ohmmeter
should indicate no continuity. If ohmmeter indicates continuity, repeat adjustment procedure.
ApplicationAuto. Trans.Man. Trans.
1.3L9-11 @ 8509-11 @ 700
1.6L Non-Turbo1-3 @ 8500-4 @ 850
1.6L Turbo10-14 @ 8500-4 @ 850
NOTE:Idle m ixture is controlled by ECA and is not adjustable.
ApplicationAuto. Trans.Man. Trans.
1.3L830-870680-720
1.6L800-900800-900
CAUT ION: DO NOT tam per with throttle stop screw at throttle lever. Doing so m ay result in dam age to throttle
body.
Page 2 of 3 MITCHELL 1 ARTICLE - D - ADJUSTMENTS 1991 ENGINE PERFORMANCE Ford/Mercury - On-Vehicle Adjustments
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B959286D2%2D3A85%2D4BFC%2D9C5C%2D
...

memory. Intermittent failures may be caused by a sensor, connector, or wiring. See INTERMITTENTS in TESTS W/O CODES article in the
ENGINE PERFORMANCE Section.
VISUAL CHECK & VEHICLE PREPARATION
Before connecting any equipment to diagnose EEC system, perform following preparatory procedures:
Verify condition of air cleaner and air ducts.
Check all vacuum hoses for leaks, restrictions, or improper routing.
Check EEC system wiring harness electrical connections for corrosion, bent or broken pins, loose wires or terminals, or improper
routing.
Check ECA, sensors, and actuators for physical damage.
Check engine oil and coolant level.
Perform all necessary safety precautions to prevent personal injury or vehicle damage.
Set parking brake. Place shift lever in Park for automatic transmissions, or Neutral for manual transmissions. DO NOT move shift lever
during test unless specifically directed.
Turn off all lights and accessories. Ensure vehicle doors are closed when measuring voltage or resistance.
Start engine. Run at idle until upper radiator hose is hot and pressurized and engine is off fast idle. Check for leaks around exhaust
manifold, exhaust gas oxygen sensor, and vacuum hose connections.
Turn ignition off. Service items as required. Go to EQUIPMENT HOOK-UP .
EQUIPMENT HOOK-UP
VOM
1. Turn ignition off. Connect a jumper wire from STI connector to ground. Refer to SELF-TEST CONNECTOR LOCATION and
SELF
-TEST CONNECTOR WIRE COLORS tables. See Fig. 1 .
2. Connect VOM between STO terminal and engine ground. Set VOM to measure 0-20 volts DC.
CHECK ENGINE Light (MIL)
Connect a jumper wire between STI connector and ground.
SUPER STAR II Tester
Turn ignition off. Connect adapter cable leads to diagnostic tester. Connect service adapter cables to vehicle self-test connectors. Ground
adapter cable.
SELF-TEST CONNECTOR LOCATION
SELF-TEST CONNECTOR WIRE COLORS

Fig. 1: Self
-Test Connector Terminal ID
Courtesy of FORD MOTOR CO.
RETRIEVING CODES
Reading Service Codes
ApplicationLocation
1.3LLeft Rear Corner Of Engine Compartment
1.6LRight Rear Corner Of Engine Compartment
CircuitWire Color
1.3L
SMLBlue/Green
STIYellow/Green
STOYellow/White
1.6L
SMLBlack/Blue
STIYellow
STOGreen/Black
Page 2 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
...

1. Turn ignition off. Install BOB. Leave ECA disconnected. Connect test light between STI test pin on BOB and 12-volt source. If test
light comes on, go to PINPOINT TEST STO
. If light does not come on, go to next step.
2. Leave test light connected. Ground STI connector. If test light does not come on, repair open circuit between STI connector and ECA.
PINPOINT TEST STO - SELF-TEST OUTPUT

Fig. 16: Identifying STI & STO Circuit & Connector

STO CIRCUIT PIN IDENTIFICATION
1. Turn ignition off. Install BOB. Leave ECA disconnected. Measure resistance between STO test pin and STO terminal of self-test
connector. If resistance is greater than 5 ohms, repair circuit between ECA and self-test connector. If resistance is less than 5 ohms, go
to next step.
2. Measure resistance between STO test pin and all other test pins. If resistance between STO test pin and any other test pin is less than 5
ohms, repair short in STO wire to diagnostic connector. If resistance is greater than 5 ohms, go to PINPOINT TEST PGC
.
PINPOINT TEST PGC - POWER & GROUND CONNECTIONS
PGC CIRCUIT PIN IDENTIFICATION
1. Turn ignition off. Install BOB, leaving ECA disconnected. Turn ignition on. Measure voltage at BOB pin in question. Compare voltage
to specification in PGC CIRCUIT PIN IDENTIFICATION
table. If voltage is not to specification, repair wire in question.
2. Measure resistance between ground and BOB pin in question. If any measurement is greater than 5 ohms, repair associated wire to
ground. If resistance is less than 5 ohms, return to PINPOINT TEST VREF
if sent here from there, and replace ECA. If not sent here
from PINPOINT TEST VREF, return to diagnostic routine.
PINPOINT TEST STG - SWITCH TO GROUND
CircuitECA PinBOB PinWire Color
STI
1.3L1K48YEL/GRN
1.6L1W48YEL
NOTE:Enter this test only when codes cannot be retrieved or when directed by PINPOINT T EST ST I.
CircuitECA PinBOB PinWire Color
STO
1.3L1F17YEL/WHT
1.6L1B17GRN/BLK
NOTE:Enter this test only when directed here from QUICK T EST S or another PINPOINT T EST .
CircuitECA PinBOB PinWire Color
1.3L
GND2A39, 40, 44, 60BLK
GND2B20BLK
GND2C16BLK
GND2D46, 49BLK
KAPWR1A1(1) WHT/RED
MT/AT (2) 2J6BLK
1.6L
GND2R49BLK
GND3A20BLK
GND3G40BLK
KAPWR3J1(1) BLU/RED
(1)Battery voltage.
(2)Manual transmission only.
NOTE:Enter this test only when directed here from QUICK T EST S or another PINPOINT T EST .
Page 16 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
...

STG CIRCUIT PIN IDENTIFICATION
1. Turn ignition off. Install BOB, leaving ECA disconnected. Measure resistance between switch BOB test pin and ground. Cycle switch. I
f
resistance is greater than 10,000 ohms with switch open and less than 5 ohms when switch is closed, switch is okay; go to step 4). If
resistance is not greater than 10,000 ohms with switch open, or greater than 5 ohms when switch is closed, go to next step.
2. Turn ignition off. Disconnect switch. Connect ohmmeter between switch terminals on 2-pin switches, or between ground and switch
ECA terminal on multi-pin or one-pin switches. Cycle switch. If resistance is not greater than 10,000 ohms with switch open, or is
greater than 5 ohms when switch is closed, replace switch. If resistance is greater than 10,000 ohms with switch open and less than 5
ohms when switch is closed, switch is okay; go to next step.
3. Turn ignition off. Install BOB, leaving ECA disconnected. Measure resistance between BOB pin for suspected switch and BOB pins 26,
37, 57, and 60. If any measurement is less than 10,000, repair shorted wire in question. If all measurements are greater than 10,000
ohms, go to next step.
4. Turn ignition off. Install BOB, leaving ECA disconnected. Measure resistance between BOB pin for suspected switch and switch
connector. If resistance is greater than 5 ohms, repair wire in question. If sent here from SWITCH MONITOR TEST in QUICK TESTS,
replace ECA; otherwise, return to QUICK TESTS.
PINPOINT TEST STP - SWITCH TO POWER
STP CIRCUIT PIN IDENTIFICATION
1. Turn ignition off. Install BOB, leaving ECA disconnected. Turn ignition on. Cycle switch in question. Measure voltage between switch
BOB test pin and ground. If voltage changes from less than 4 volts to more than 10 volts, switch is okay. If sent here from SWITCH
MONITOR TEST in QUICK TESTS, replace ECA. If sent here from elsewhere in QUICK TESTS, return to QUICK TESTS. If voltage is
not as specified, go to next step.
2. Turn ignition on. Measure voltage at switch in question on wire to ECA. Cycle switch. If voltage changes from less than 4 volts to more
than 10 volts, repair wire from switch to ECA. If voltage does not change from less than 4 volts to more than 10 volts, go to next step.
3. Turn ignition on. Install BOB, leaving ECA disconnected. Measure resistance between BOB test pin for switch in question and ground
and between BOB test pin and BOB pins 37, 57, and 26. If resistance is greater than 10,000 ohms for all measurements, go to next step.
If resistance is not greater than 10,000 ohms for all measurements, repair wire to switch.
4. Disconnect switch. Measure resistance between switch terminals. Cycle switch. If resistance is less than 5 ohms with switch closed and
greater than 10,000 ohms with switch open, switch is okay. If sent here from SWITCH MONITOR TEST in QUICK TESTS, return to
QUICK TESTS. If sent here from elsewhere in QUICK TESTS, replace ECA. If resistance is not as specified, replace switch.
PINPOINT TEST VPWR - VEHICLE POWER
SwitchECA PinBOB PinWire Color
1.3L
ACS1Q10BLU/RED
BLMT1S23GRN
IDL1N18YEL/BLK
NGS/CES (1) 1V43BLU/WHT
PSPS1P19PNK
WOT2L27YEL
1.6L
BPS (2) 2L12LT GRN/BLK
IDL1E18GRN/ORG
NGS/CES (1) 1G8RED/BLU
PSPS1K19GRN/RED
(1)Manual transmission only.
(2)Turbo only.
NOTE:For 1.3L, blower m otor resistor m ust be disconnected, HEAT ER fuse m ust be rem oved, and blower
m otor switch m ust be in position "1" when testing ACS signal.
NOTE:Enter this test only when directed here from QUICK T EST S.
SwitchECA PinBOB PinWire Color
1.3L
ACS1Q10GRN
BOO1O2GRN/RED
DEF1T30BLK/BLU
Fan1R22YEL/RED
HLDT1U28WHT
VST1C5BLK/RED
1.6L
BOO1J3WHT/GRN
VST3B5BLK/RED
NOTE:Enter this test only when directed here from another PINPOINT T EST . T o prevent replacem ent of good
com ponents, note following non-EEC com ponents m ay be faulty: ignition switch, alternator, battery
cables, ground straps, or voltage regulator. T his test is intended to diagnose only ECA, wiring harness
circuits, and battery voltage.
Page 17 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
...

CLUTCH ENGAGE SWITCH (CES)
This switch is located on the manual transaxle and informs the ECA of transmission operating conditions. The ECA uses this data fo r id l e
speed control and canister purge valve operation.
CRANKSHAFT POSITION SENSOR (CPS) (FESTIVA)
This sensor is located in the distributor and sends engine RPM and crankshaft position data to the ECA. The ECA uses this data in calculating
fuel metering, ignition timing, idle speed control and canister purge valve operation.
CYLINDER IDENTIFICATION SENSOR (CID) (CAPRI)
This sensor is located in the distributor and provides crankshaft position data to the ECA. The ECA uses this data in calculating fuel metering
and ignition timing.
ELECTRICAL LOAD SWITCHES
Blower control, cooling fan, rear window defroster, air conditioning and headlight switches all send signals to the ECA. The ECA uses these
signals for idle speed control.
ENGINE COOLANT TEMPERATURE (ECT) SENSOR
This sensor is located in the intake manifold and sends coolant temperature data to the ECA. The ECA uses this data in calculating fuel
metering, idle speed control and canister purge valve operation.
EXHAUST GAS OXYGEN (EGO) SENSOR
This sensor is located in the exhaust manifold and senses oxygen concentration in the exhaust gas. The ECA uses this data in calculating fuel
metering, idle speed control and canister purge valve operation.
NEUTRAL SAFETY SWITCH (A/T)
This switch is located on the automatic transaxle and sends a signal to the ECA whenever the transaxle is in Neutral or Park ranges. The ECA
uses this signal in calculating fuel metering, idle speed control and canister purge valve operation.
POWER STEERING PRESSURE SWITCH (PSPS)
This switch is located on the power steering pump and sends data about power steering operation to the ECA. The ECA uses this data for idle
speed control.
THROTTLE POSITION SENSOR (TP)
This device is located on the throttle body and contains 2 switches. The Wide Open Throttle (WOT) Switch sends a signal to the ECA when
throttle valve opening is more than 70 degrees. The ECA uses this signal in calculating fuel metering.
The Idle Switch (IDL) sends a signal to the ECA when throttle valve opening is less than 1.5 degrees. The ECA uses this signal for idle speed
control and canister purge valve operation.
VANE AIRFLOW (VAF) METER
This sensor is located in the air cleaner housing and sends intake airflow data to the ECA. The ECA uses this data in calculating fuel metering.
VANE AIR TEMPERATURE (VAT) SENSOR
This sensor is located inside the vane airflow sensor and senses intake air temperature. The ECA uses this data in calculating fu el met erin g,
idle speed control and canister purge valve operation.
CEC OUTPUT SIGNALS
CANISTER PURGE (CANP) SOLENOID
See EMISSION SYSTEMS.
CHECK ENGINE LIGHT
See SELF-DIAGNOSTIC SYSTEM.
FUEL INJECTORS
See FUEL CONTROL.
IDLE SPEED CONTROL BY-PASS AIR (ISC-BPA) VALVE
See IDLE SPEED. NOTE:Vehicles are equipped with different com binations of com puter-controlled com ponents. Not all
com ponents listed below are used on every vehicle. For theory and operation of each output
com ponent, refer to indicated system .
Page 2 of 6 MITCHELL 1 ARTICLE - E - THEORY/OPERATION 1991 ENGINE PERFORMANCE Ford/Mercury Theory & Operation
3/10/2009 http://www.eautorepair.net/app/PrintItems.asp?S0=2097152&S1=0&SG=%7B7DD6473C%2DB5BB%2D4F20%2D9D70%2D
...