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. For component locations, see COMPONENT LOCATIONS .
IGNITION SYSTEM
| CAUTION | When battery is disconnected, radio will go into anti-theft protection mode. Obtain radio anti-theft protection code from owner prior to servicing vehicle. |
Note. Use illustrations for component and component connector locations. See COMPONENT LOCATIONS .
Removal
CMP sensor, is located on rear of left cylinder head. Disconnect negative battery terminal. Remove mounting bolts and sensor. To replace oil seal, remove CMP sensor mounting plate. Install Seal Extractor Holder (2085/1) and Seal Extractor (3240). Remove seal.
Installation
Clean sealing surface. Install seal to the stop using Installer (3241). Install CMP sensor mounting plate and CMP sensor.
Removal & Installation
CKP sensor is located on lower left rear side of cylinder block. Disconnect negative battery terminal. Remove necessary components to access sensor. Remove sensor mounting bolt and sensor. To install, reverse removal procedure.
RPM sensor is located on upper left rear side of cylinder block. Sensor mounting bracket is adjusted at factory. Before removal, mark sensor mounting bracket for reassembly reference. Disconnect negative battery terminal. Remove sensor mounting bolts and sensor. To install, reverse removal procedure.
The KS I and KS II are located beneath intake manifold. KS can be removed without removing intake manifold. Disconnect negative battery terminal. Using a long 8-mm Allen Wrench (3247), remove KS mounting bolt and KS. To install, reverse removal procedure. Tighten bolts to specification. See TORQUE SPECIFICATIONS .
FUEL SYSTEM
| CAUTION | When battery is disconnected, radio will go into anti-theft protection mode. Obtain radio anti-theft protection code from owner prior to servicing vehicle. |
| WARNING | Always relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components. |
FUEL SYSTEM PRESSURE RELEASE
- Remove fuel pump relay from fuse panel. Start engine. Let engine run until it stops. Turn ignition off. Disconnect negative battery terminal. Install fuel pump relay.
- Use a rag to cover fuel system connection before disconnecting high pressure fuel system component for test or repair procedure. Some residual fuel pressure may still be in system.
FUEL INJECTORS
| WARNING | ALWAYS relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components. |
Disconnect negative battery terminal. Disconnect fuel lines from fuel supply manifold. Remove fuel rail mounting bolts and lift fuel rail with injectors. Remove injectors from fuel rail. (Scheme 1) To install, reverse removal procedure.
Scheme 1
FUEL FILTER
In all models fuel filter is located on frame rail near fuel tank. (Scheme 2) In some cases in may be necessary to remove the aerodynamic trim panel from under vehicle to gain access to fuel tank and filter. Before removing or replacing fuel filter, release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE. Whenever fuel lines are removed from fuel filter on fuel filters that use hose clamps to secure fuel lines, ensure that clamps are in good working order or replace as necessary. On fuel filter that use banjo style fittings, always replace sealing rings with NEW parts. Anytime fuel filter has been removed, after installation start vehicle and check for leaks.
Scheme 2
- Observe fuel system warnings and notes. Release fuel pressure. See «FUEL SYSTEM PRESSURE RELEASE»(/audi/a6/c4-1994-1997/remont/removal-installation/#engine-controls-removeinstalloverhaul__fuel-system-pressure-release). Turn ignition off and remove ignition key from vehicle. Disconnect negative battery cable. Working in luggage compartment, remove fuel pump access plate. Noting orientation of fuel lines, mark and remove 4 fuel lines. Disconnect fuel pump and fuel level sensor harness connector.
- Using Union Nut Wrench (3087), remove union nut. Remove cover flange and "O" ring seal. Disconnect fuel level sensor harness connector from inside of flange cover. Disconnect return line from inside of cover flange. (Scheme 3)
- Insert Fuel Pump Wrench (3214) through opening in fuel tank, turn fuel pump along with inner section of baffle housing about.59" (15 mm) to the left. (Scheme 4) Remove fuel pump assembly through opening.
- Remove supply line from fuel pump. Remove power and ground wires from fuel pump. Fuel pump baffle housing come in 2 different versions. Type 1 uses a bayonet style fitting for filter screen, type 2 uses a welded filter screen. Ensure that appropriate style baffle housing is fitted. (Scheme 5)
- Install new fuel pump to baffle housing. Connect power and ground wires to fuel pump. Connect fuel supply line to fuel pump. Install fuel pump assembly through opening. Place inner baffle housing into outer housing so that notch (1) on inner housing matches mark (2) on outer housing. (Scheme 6) When installing inner housing an audible click should be heard when housing is seated. Using fuel pump wrench turn inner housing about.59" (15 mm) to the right. Notch (1) on inner housing should now match mark (3) on outer housing.
- Connect return line and fuel level sensor harness connector to cover flange. Using NEW "O" ring seal install cover flange. Install union nut, using union nut wrench torque nut to 15 ft. lbs. (20 N.m). Connect harness connector and fuel lines. Re-install cover plate. Connect negative battery cable. Reprogram radio, clock and power windows as necessary.
Scheme 3
Scheme 4
Scheme 5
Scheme 6
SENSORS
| CAUTION | When battery is disconnected, radio will go into anti-theft protection mode. Obtain radio anti-theft protection code from owner prior to servicing vehicle. |
Note. Use illustrations for component and component connector locations. See COMPONENT LOCATIONS .
A HO2S is mounted in each exhaust pipe in front of catalytic converters. Disconnect negative battery terminal. Disconnect permanent pigtail from sensor. Ensure sensor is free of contaminants. Avoid using any cleaning solvents. Sensor may be difficult to remove when engine temperature is less than 118°F (48°C). To install, reverse removal procedure. Always use anti-seize compound on threads before installation. Tighten sensor to specification. See TORQUE SPECIFICATIONS .
- Remove air filter, and unscrew stop bracket. Using heat gun, heat locking compound on fastening bolt. Remove bolt slowly. DO NOT damage threads. Clean locking compound from bolt hole threads.
- Install MAF sensor plate. Ensure 5 dimple marks face up. Lightly tighten self-locking screw. Ensure MAF plate is centered and rest position is correct. To complete installation, reverse removal procedure.
PCM is located in the passenger footwell on back of evaporator case. Disconnect negative battery terminal. To remove, pull carpet back and remove cover of plastic housing containing PCM. Remove PCM from housing. To install, reverse removal procedure.
2.8L
Note. For timing belt replacement procedure, see appropriate TIMING BELT article in ENGINES.
COMPONENT LOCATIONS
Use following illustrations to locate engine performance related components. (Scheme 7)- (Scheme 10).
Scheme 7
Scheme 8
Scheme 9
Scheme 10
TORQUE SPECIFICATIONS
| Application | Ft. Lbs. (N.m) |
|---|---|
| ECT Sensor | 15 (20) |
| Fuel Return Line Fitting | 18 (24) |
| Fuel Supply Line Union Bolts | 18 (24) |
| HO2S | 37 (50) |
| Intake Manifold Assembly Bolts | 15 (20) |
| Knock Sensor Bolts | 18 (24) |
| Throttle Body Mounting Bolts | 15 (20) |
| INCH Lbs. (N.m) | |
| CMP Sensor | 84 (9.5) |
| EGR Valve Mounting Bolts | 84 (9.5) |
| Fuel Rail Bolts | 84 (9.5) |
| IAC Valve Bolt | 53 (6.0) |
| IAC Valve Nut | 84 (9.5) |
TORQUE SPECIFICATIONS