1993 VOLKSWAGEN CORRADO fuel pressure

H - TESTS W/O CODES
Article Text (p. 3)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
NOTE: Symptoms listed are for CIS-E Motronic system. When working
on Digifant and Motronic systems, use symptoms listed only
as a diagnostic guide. A list of specific symptoms for
Digifant and Motronic systems is not available from
manufacturer.
ENGINE DOES NOT START OR IS DIFFICULT TO START WHEN COLD
* Check for insufficient fuel in tank.
* Check fuel pump relay and fuel pump.
* Check fuel system for leaks.
* Check auxiliary air intake system.
* Check fuel system after-start, acceleration enrichment and
warm-up circuits.
* Check cold-start valve.
* Check airflow sensor lever adjustment and control plunger.
* Check sensor plate rest position and idle circuit.
* Check fuel system differential and residual pressures.
* Check fuel injection volume.
* Check engine coolant temperature sensor.
* Check ignition timing, spark plugs, distributor, secondary
ignition wiring and coil.
* Check Hall Effect sensor.
* Check ignition coil power output stage.
ENGINE DOES NOT START OR IS DIFFICULT TO START WHEN WARM
* Check radiator cooling fan after-run circuit.
* Check fuel pump check valve.
* Check fuel evaporative frequency solenoid(s).
* Check fuel system for leaks.
* Check auxiliary air intake system.
* Check idle speed.
* Check fuel system after-start, acceleration enrichment and
warm-up circuits.
* Check cold-start valve.
* Check injector fuel pressure and volume.
* Check sensor plate rest position and idle circuit.
* Check sealing ring under control plunger.
* Check fuel system differential and residual pressures.
* Check engine coolant temperature sensor.
* Check ignition timing, spark plugs, distributor, secondary
ignition wiring and coil.
UNEVEN IDLE OR NO IDLE WITH COLD ENGINE OR DURING WARM-UP
* Check fuel evaporative frequency solenoid(s).
* Check fuel system for leaks.
* Check auxiliary air intake system.
* Check idle speed.
* Check oxygen sensor control circuit.

H - TESTS W/O CODES
Article Text (p. 4)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
* Check cold-start valve.
* Check injector fuel pressure and volume.
* Check throttle potentiometer.
* Check fuel system differential and residual pressures.
* Check idle switch.
* Check engine coolant temperature sensor.
* Check exhaust system.
* Check ignition timing and spark plugs.
ENGINE STARTS BUT STALLS
* Check fuel pump relay and fuel pump.
* Check auxiliary air intake system.
* Check idle speed.
* Check fuel system after-start, acceleration enrichment and
warm-up circuits.
* Check airflow sensor lever adjustment and control plunger.
* Check sensor plate rest position and idle circuit.
* Check fuel system differential and residual pressures.
* Check idle switch.
* Check engine coolant temperature sensor.
IDLE SPEED EXCEEDS SPECIFICATION
* Check throttle cable adjustment.
* Check fuel evaporative frequency solenoid(s).
* Check auxiliary air intake system.
* Check idle speed.
* Check throttle potentiometer.
* Check idle switch.
* Check engine coolant temperature sensor.
* Check throttle body basic adjustment.
* Check ignition timing.
POOR ACCELERATION WITH COLD ENGINE OR DURING WARM-UP
* Check fuel pump.
* Check auxiliary air intake system.
* Check oxygen sensor control circuit.
* Check fuel system after-start, acceleration enrichment and
warm-up circuits.
* Check airflow sensor lever adjustment and control plunger.
* Check throttle potentiometer.
* Check fuel system differential and residual pressures.
* Check injector fuel pressure and volume.
* Check idle switch.
* Check engine coolant temperature sensor.
* Check throttle body basic adjustment.
* Check exhaust system.
* Check ignition timing, spark plugs, distributor, secondary
ignition wiring and coil.

H - TESTS W/O CODES
Article Text (p. 5)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
ENGINE STALLS WHILE DRIVING
* Check fuel pump.
* Check auxiliary air intake system.
* Check injector fuel pressure and volume.
* Check idle and full throttle switches.
* Check intake air preheating system.
* Check ignition timing, spark plugs, distributor, secondary
ignition wiring and coil.
POOR PERFORMANCE
* Check fuel pump.
* Check throttle cable adjustment.
* Check auxiliary air intake system.
* Check airflow sensor lever adjustment and control plunger.
* Check throttle potentiometer.
* Check fuel system differential and residual pressures.
* Check injector fuel pressure and volume.
* Check full throttle switch.
* Check mass airflow sensor (if equipped).
* Check intake air preheating system.
* Check catalytic converter.
* Check ignition timing.
ENGINE RUN-ON (DIESELING)
* Check fuel evaporative frequency solenoid(s).
* Check fuel system for leaks.
* Check cold-start valve.
* Check injector fuel pressure and volume.
* Check airflow sensor lever adjustment and control plunger.
HIGH FUEL CONSUMPTION
* Check fuel system for leaks.
* Check oxygen sensor control circuit.
* Check cold-start valve.
* Check injector fuel pressure and volume.
* Check airflow sensor lever adjustment and control plunger.
* Check throttle potentiometer.
* Check injector fuel pressure and volume.
* Check full throttle switch.
* Check mass airflow sensor (if equipped).
* Check intake air preheating system.
* Check exhaust system for leaks (between cylinder and
oxygen (O2) sensor).
* Check ignition timing.
ENGINE KNOCK
* Check knock sensors (if equipped).

H - TESTS W/O CODES
Article Text (p. 6)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
* Check full throttle switch.
* Check ignition timing.
ENGINE RUNS UNEVENLY OVER ENTIRE SPEED RANGE
* Check auxiliary air intake system.
* Check injector fuel pressure and volume.
* Check ignition timing, spark plugs, distributor, secondary
ignition wiring and coil.
INTERMITTENTS
INTERMITTENT PROBLEM DIAGNOSIS
Intermittent fault testing requires duplicating circuit or
component failure to identify the problem. These procedures may lead
to the computer setting a fault code (on some systems) which may help
in diagnosis.
If problem vehicle does not produce fault codes, monitor
voltage or resistance values using a DVOM while attempting to
reproduce conditions causing intermittent fault. A status change on
DVOM indicates a fault has been located.
Use a DVOM to pinpoint faults. When monitoring voltage,
ensure ignition switch is in ON position or engine is running. Ensure
ignition switch is in OFF position or negative battery cable is
disconnected when monitoring circuit resistance. Status changes on
DVOM during test procedures indicate area of fault.
TEST PROCEDURES
Intermittent Simulation
To reproduce the conditions creating an intermittent fault,
use the following methods:
* Lightly vibrate component.
* Heat component.
* Wiggle or bend wiring harness.
* Spray component with water.
* Remove/apply vacuum source.
Monitor circuit/component voltage or resistance while
simulating intermittent. If engine is running, monitor for self-
diagnostic codes. Use the test results to identify a faulty component
or circuit. For system or component testing refer to the appropriate
I - SYS/COMP TESTS article in this section. See the menu below:
* For Cabriolet, see: I - SYSTEM/COMPONENT TESTS
* For Corrado SLC, see: I - SYSTEM/COMPONENT TESTS
* For EuroVan, see: I - SYSTEM/COMPONENT TESTS
* For Fox, see: I - SYSTEM/COMPONENT TESTS
* For Golf, GTI, Jetta, see: I - SYSTEM/COMPONENT TESTS
* For Passat GL 2.0L 4-Cylinder, see:

I - SYSTEM/COMPONENT TESTS
Article Text (p. 3)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:11PM
tester. Scan tester value must decrease. If temperature value does not
change, repair intake air temperature sensor circuit or replace sensor
as necessary. After repairs, erase Diagnostic Trouble Code (DTC)
memory (if applicable) and select END OUTPUT function.
HALL EFFECT SENSOR
Corrado SLC (2.8L)
Testing information is not available from manufacturer. These
vehicles are equipped with a distributorless ignition system.
FUEL SYSTEM
ACCELERATION/FULL THROTTLE ENRICHMENT & DECELERATION FUEL
CUT-OFF
Corrado SLC (2.8L)
1) Ensure engine coolant temperature is at least 176øF
(80
øC). Connect Scan Tester (VAG 1551) to Data Link Connectors (DLC)
located in center console, in front of shift lever.
2) Start engine and allow it to idle. With scan tester in
READ TEST VALUE BLOCK function, select group No. 04 and read value in
field No. 4 of scan tester. Display value must be 00010 at idle.
3) Using accelerator pedal, increase engine speed to 3000 RPM
and observe scan tester. Display value in field No. 4 of scan tester
must briefly be 10100. Release accelerator pedal and observe scan
tester.
4) Display value in field No. 4 of scan tester must briefly
be 00011, then return to 00010 at idle. If values are not as
specified, see THROTTLE POSITION (TP) SENSOR ADJUSTMENT procedures in
the D - ADJUSTMENTS article. If values are as specified, select END
OUTPUT function on scan tester.
FUEL INJECTORS & CIRCUIT
Corrado SLC (2.8L)
1) To access fuel injectors, remove ignition wires. Remove
hose from mass airflow sensor. Disconnect hose to fuel evaporative
(frequency) solenoid valve at throttle body.
2) Disconnect throttle position sensor and idle air control
valve. Disconnect accelerator cable from throttle body. Disconnect and
plug coolant hoses at throttle body.
3) Disconnect hose from air intake heated tube. Detach fuel
lines at cylinder head cover and remove from fuel rail. Disconnect
vacuum hose from fuel pressure regulator. Remove intake manifold upper
section. See Fig. 2.
4) With intake manifold upper section removed, disconnect
wiring harness from fuel injectors. Using a Digital Volt-Ohmmeter
(DVOM) and test leads from Adapter Kit (VW 1594), check fuel injector
resistance. See Fig. 3.
5) Fuel injector resistance should be 15.0-21.5 ohms. If
resistance is zero ohms, check for a short circuit in wiring harness.

MAINTENANCE INFORMATION
Article Text (p. 11)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:14PM
Application Quantity (1)
A/C System R-12 Refrigerant
1990-92 (up to 7/92) ............................. 37-40 Ozs.
A/C System R-134a Refrigerant (2)
1993-94 (from 7/92) ........................... 28.2-31.8 Ozs.
Cooling System
4-Cyl. ...................................... 6.8 Qts. (6.5L)
V6 .......................................... 9.1 Qts. (8.6L)
Engine Oil (3)
4-Cyl. ...................................... 4.3 Qts. (4.0L)
V6 .......................................... 6.3 Qts. (6.0L)
Fuel Tank
4-Cyl. ..................................... 14.5 Gals. (55L)
V6 ......................................... 18.5 Gals. (55L)
Automatic Transmission
Fluid Change ................................ 3.2 Qts. (3.0L)
Overhaul .................................... 5.9 Qts. (5.6L)
Manual Transmission ........................... 2.1 Qts. (2.0L)
Final Drive
Differential (A/T) (4) ....................... 0.8 Qt. (.75L)
(1) - Capacities are recommended or calculated levels. Always use
dipstick (if available) to measure level.
(2) - Use of R-12 in a R134a system will result in SEVERE DAMAGE.
(3) - Includes oil filter change.
(4) - Lifetime fill.ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ WHEEL & TIRE SPECIFICATIONS
Wheel and tire sizes vary according to vehicle and equipment
and can be found on tire information label on each vehicle. Wheel and
tire specifications and tire inflation pressures are listed on a label
found inside fuel tank flap.
NOTE: Snow chains must be used on drive wheels, in pairs only.
WHEEL TIGHTENING
Tighten all wheel lugs to 80 ft. lbs. (110 N.m).
BATTERY SPECIFICATIONS
CAUTION: When battery is disconnected, vehicles equipped with
computers may lose memory data. When battery power is
restored, driveability problems may exist on some vehicles.
These vehicles may require a relearn procedure. See COMPUTER
RELEARN PROCEDURES article in the GENERAL INFORMATION
section.
All models use BCI group 41 batteries with cold crank rating

N - REMOVE/INSTALL/OVERHAUL
Article Text
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:21PM
ARTICLE BEGINNING
1993 ENGINE PERFORMANCE
Removal, Overhaul & Installation
Corrado SLC
CAUTION: When battery is disconnected, vehicle computer and memory
systems may lose memory data. Driveability problems may
exist until computer systems have completed a relearn
cycle. See the COMPUTER RELEARN PROCEDURES article in
GENERAL INFORMATION before disconnecting battery.
INTRODUCTION
Removal, overhaul and installation procedures are covered in
this article. If component removal and installation is primarily an
unbolt and bolt-on procedure, only a torque specification may be
furnished.
CAUTION: When disconnecting battery, obtain and record radio
anti-theft code. If wrong code is entered into radio after
power is restored, radio will become inoperable.
IGNITION SYSTEM
NOTE: Corrado SLC ignition system removal and installation
information not available from manufacturer. These vehicles
are equipped with a distributorless ignition system.
DISTRIBUTOR
FUEL SYSTEM
FUEL SYSTEM PRESSURE RELEASE
To relieve fuel system pressure, remove fuel pump fuse (No.
5, 13 or 18) or fuel pump relay to deactivate fuel pump. Place a clean
shop rag around fuel line fitting and slowly loosen fitting.
WARNING: Fuel system pressure release procedure is not available
from manufacturer. Fuel will discharge when disconnecting
fuel system components. Disconnect ignition coil output
stage wiring harness to deactivate ignition. DO NOT smoke
or work near heaters or other fire hazards. Keep a fire
extinguisher handy.
FUEL PUMP
Removal & Installation (Corrado SLC)
1) Obtain and record radio anti-theft code. Disconnect

N - REMOVE/INSTALL/OVERHAUL
Article Text (p. 2)
1993 Volkswagen Corrado
For Volkswagen Technical Site: http://vw.belcom.ru
Copyright © 1998 Mitchell Repair Information Company, LLC
Wednesday, March 22, 2000 09:21PM
negative battery cable. Remove luggage compartment floor covering and
fuel pump access cover. Disconnect wiring harness and fuel lines from
fuel pump.
2) Using Wrench (3217), loosen fuel pump screw cap. Remove
flange and sealing ring from fuel tank opening. Loosen fuel pump by
twisting it to left. Remove fuel pump from fuel tank.
3) When installing fuel pump, ensure that fuel gauge sending
unit is not bent. Sending unit must be installed with a frontal angle
of 5 degrees. Align mark on flange with fuel tank. To complete
installation, reverse removal procedure.
FUEL PUMP CHECK VALVE
FUEL RAIL & INJECTORS
Removal & Installation (Corrado SLC)
1) Remove ignition wires. Remove hose from mass airflow
sensor. Disconnect hose to fuel evaporative (frequency) solenoid valve
at throttle body.
2) Disconnect throttle position sensor and idle air control
valve. Disconnect accelerator cable from throttle body. Disconnect and
plug coolant hoses at throttle body.
3) Disconnect hose from air intake heated tube. Detach fuel
lines at cylinder head cover and remove from fuel rail. Disconnect
vacuum hose from fuel pressure regulator. Remove upper intake
manifold.
4) With upper intake manifold removed, disconnect wiring
harness from fuel injector(s). Pry off retaining clip(s) from
injector(s). To install injectors, lubricate "O" rings with fuel. To
complete installation, reverse removal procedure.
TORQUE SPECIFICATIONS
TORQUE SPECIFICATIONS (CORRADO SLC)ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄApplication Ft. Lbs. (N.m)
EGR Temperature Sensor ...................... 15 (20)
Knock Sensors ............................... 18 (25)
Oxygen Sensor ............................... 37 (50)
Throttle Body Bolts ......................... 18 (25)
Upper Intake Manifold Bolts ................. 18 (25)
INCH Lbs. (N.m)
FUEL RAIL BOLTS ............................. 84 (10)
Intake Air Temperature Sensor ............... 84 (10)
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄEND OF ARTICLE