ENGINE COMPRESSION
Check engine compression at normal operating temperature with all spark plugs removed. To prevent damage to catalytic converter, make tests quickly and only when necessary.
Note. Compression specifications are not supplied by manufacturer. Difference between cylinders must not exceed 25%.
VALVE CLEARANCE
Note. All models are equipped with hydraulic lifters. No adjustments are required.
IGNITION COIL
| Application | Primary | Secondary |
|---|---|---|
| Discovery Series I | 0.80 | 13,000 |
| Except Discovery Series I | 0.45-0.55 | 12,000-14,600 |
IGNITION COIL RESISTANCE - Ohms @ 68°F (20°C)
SPARK PLUGS
| Application | Champion No. |
|---|---|
| Discovery Series I | RN11YCC |
| Except Discovery Series I | (1) RC11PYPB4 |
| (1) Do not attempt to adjust gap of RC11PYB4 spark plugs. | |
| (1) | Do not attempt to adjust gap of RC11PYB4 spark plugs. |
SPARK PLUG TYPE
| Application | Gap In. (mm) | Torque Ft. Lbs. (N.m) |
|---|---|---|
| Discovery Series I | 0.035-0.040 (0.89-1.02) | 14-16 (19-22) |
| Except Discovery Series I | 0.038-0.042 (0.95-1.05) | 14-16 (19-22) |
SPARK PLUG SPECIFICATIONS
Scheme 1
Scheme 2
IGNITION TIMING
On Discovery Series I, ignition timing is controlled by Land Rover's Generic Engine Management System (GEMS) through the Engine Control Module (ECM) and is not adjustable. ECM, using Knock Sensor (KS), Camshaft Position (CMP) sensor and Crankshaft Position (CKP) sensor signals, can adjust each cylinder according to individual needs. Based on engine speed and load an optimum ignition timing can be set for each cylinder. As a result, there can be 8 different settings simultaneously. Always refer to SERVICE INFORMATION underhood label in engine compartment. If underhood label and manual specifications differ, always use underhood label specifications.
On Discovery Series II and Range Rover, ignition timing is controlled by Bosch Motronic M5.2.1 engine management system through the ECM and is not adjustable. ECM calculates ignition timing using input signals from the Crankshaft Position (CKP) sensor, Knock Sensor (KS), Mass Airflow (MAF) sensor, Throttle Position (TP) sensor (idle only) and Engine Coolant Temperature (ECT) sensor. ECM calculates dwell timing from battery voltage and engine speed. Individual cylinder spark timing is calculated based on engine speed, load and coolant temperature, knock control, automatic gearbox shift control and idle speed control.
| Application | Specification |
|---|---|
| Discovery Series I | (2) |
| Discovery Series II | (3) 12° |
| Range Rover | (3) 12° |
| (1) Idle speed and timing are computer controlled and are not adjustable. (2) Information not available from manufacturer. (3) Expected value of ignition timing at normal operating temperature. | |
| (1) | Idle speed and timing are computer controlled and are not adjustable. |
| (2) | Information not available from manufacturer. |
| (3) | Expected value of ignition timing at normal operating temperature. |
IGNITION TIMING (Degrees BTDC) (1)
Regulated Fuel Pressure
There are 8 fuel injectors, one per cylinder which the ECM operates sequentially. On Discovery Series I, regulated fuel pressure should be 35-37 psi (2.5-2.6 kg/cm 2 ) and varies depending on amount of intake manifold vacuum acting on fuel pressure regulator. On Discovery Series II and Range Rover, all 8 injectors are fed from a common fuel rail as part of a returnless fuel system. Fuel pressure is maintained at a approximately 50-52 psi (3.5-3.6 kg/cm 2 ) by a regulator that is integral with the fuel pump.
FUEL INJECTOR RESISTANCE
| Application | Ohms |
|---|---|
| Discovery Series I | 15.7-16.7 |
| Except Discovery Series I | 13.8-15.2 |
FUEL INJECTOR RESISTANCE - Ohms @ 68°F (20°C)
IDLE SPEED & MIXTURE
Note. Engine idle speed and mixture are controlled by ECM based on signals from various sensors and are not adjustable. Values given in IDLE SPEED & MIXTURE SPECIFICATIONS table are for verification purposes only. Always refer to SERVICE INFORMATION underhood label in engine compartment. If underhood label and manual specifications differ, always use underhood label specifications.
| Application | Specification | ||
|---|---|---|---|
| Base Idle Speed (1) | |||
| Discovery Series I | |||
| In Neutral With A/C Off | 597-653 | ||
| In Neutral With A/C On | 672-728 | ||
| Discovery Series II (2) | 610-710 RPM | ||
| Range Rover (2) | 660 RPM | ||
| CO @ Idle | |||
| Range Rover | (3) | ||
| Discovery Series I & II | Less Than 0.5% | ||
| (1) Idle speed is controlled by ECM through Idle Air Control (IAC) valve. With engine at normal operating temperature, IAC valve should be set to 20-25 steps. (2) In Neutral with A/C off. (3) Information not available from manufacturer. | |||
| (1) | Idle speed is controlled by ECM through Idle Air Control (IAC) valve. With engine at normal operating temperature, IAC valve should be set to 20-25 steps. |
| (2) | In Neutral with A/C off. |
| (3) | Information not available from manufacturer. |
IDLE SPEED & MIXTURE SPECIFICATIONS