ENGINE COMPRESSION
To check engine compression, bring engine to normal operating temperature. Remove air intake hose from throttle body. Remove all spark plugs. Fully open throttle. Ensure engine cranking speed is at least 250 RPM when measuring compression.
| Application | Specification |
|---|
| Compression Ratio | 10.4:1 |
| Compression Pressure | 178 psi (12.5 kg/cm 2 ) |
| Minimum Compression Pressure | 142 psi (10.0 kg/cm 2 ) |
| Maximum Variation Between Cylinders | 14 psi (1.0 kg/cm 2 ) |
COMPRESSION SPECIFICATIONS
VALVE CLEARANCE
| Application | (1) In. (mm) |
|---|
| Intake | .006-.010 (.15-.26) |
| Exhaust | .010-.014 (.26-.36) |
| (1) Check and adjust valves with engine cold. |
| (1) | Check and adjust valves with engine cold. |
VALVE CLEARANCE SPECIFICATIONS
IGNITION COIL
| Application | Primary | Secondary |
|---|
| Cold (1) | .36-.55 | 9000-15,400 |
| Hot (2) | .45-.65 | 11,400-18,100 |
| (1) Coil temperature of 14-122°F (-10-50°C). (2) Coil temperature of 123-212°F (51-100°C). |
| (1) | Coil temperature of 14-122°F (-10-50°C). |
| (2) | Coil temperature of 123-212°F (51-100°C). |
IGNITION COIL RESISTANCE (OHMS)
DISTRIBUTOR SENSORS
| Application | Ohms |
|---|
| Camshaft Sensor |
| Cold (2) | 835-1400 |
| Hot (3) | 1060-1645 |
| Crankshaft Sensor |
| Cold (2) | 835-1400 |
| Hot (3) | 1060-1645 |
| (1) Ignition system uses 2 distributors (one at front end of each cylinder head). ECM controls ignition system based on signals from camshaft sensor (one on each distributor housing) and crankshaft sensor (at crankshaft pulley). (2) 14-122°F (-10-50°C). (3) 123-212°F (51-100°C). |
| (1) | Ignition system uses 2 distributors (one at front end of each cylinder head). ECM controls ignition system based on signals from camshaft sensor (one on each distributor housing) and crankshaft sensor (at crankshaft pulley). |
DISTRIBUTOR SENSOR RESISTANCE (1)
HIGH TENSION WIRE RESISTANCE
| Application | Ohms |
|---|
| LS400 | 25,000 Maximum |
HIGH TENSION WIRE RESISTANCE
SPARK PLUGS
| Application | NGK No. |
|---|
| LS400 | BKR6EP-11 |
| Application Type | Gap In. (mm) | Torque Ft. Lbs. (N.m) |
|---|
| New Plug | .043 (1.10) | 13 (17) |
| Maximum Wear (1) | .051 (1.30) | 13 (17) |
| (1) Replace spark plug if gap exceeds specification. |
| (1) | Replace spark plug if gap exceeds specification. |
SPARK PLUG SPECIFICATIONS
FIRING ORDER & CYLINDER NUMBERING
| Application | Firing Order |
|---|
| LS400 | 1-8-4-3-6-5-7-2 |
| Application | (1) Cylinder Number |
|---|
| Left Bank (2) | 1-3-5-7 |
| Right Bank (2) | 2-4-6-8 |
| (1) Starting at cylinder closest to timing belt-end of engine. (2) As viewed from flywheel-end of engine. |
| (1) | Starting at cylinder closest to timing belt-end of engine. |
| (2) | As viewed from flywheel-end of engine. |
IGNITION TIMING
| Application | (1) Base Timing | (2) Controlled Timing |
|---|
| LS400 | 8-12 @ 650-750 | (3) |
| (1) Jumper wire connected between terminals TE1 and E1 of DLC No. 1. (2) Jumper wire disconnected from DLC No. 1. (3) Information is not available from manufacturer. |
| (1) | Jumper wire connected between terminals TE1 and E1 of DLC No. 1. |
| (2) | Jumper wire disconnected from DLC No. 1. |
| (3) | Information is not available from manufacturer. |
IGNITION TIMING (Degrees BTDC @ RPM)
FUEL SYSTEM
| Application Type | At Idle W/Vacuum psi (kg/cm 2 ) | At Idle W/O Vacuum psi (kg/cm 2 ) |
|---|
| LS400 | 28-34 (2.0-2.4) | 38-44 (2.7-3.1) |
INJECTOR RESISTANCE
| Application | Ohms |
|---|
| LS400 | 13.4-14.2 |
INJECTOR RESISTANCE SPECIFICATIONS - Ohms @ 68°F (20°C)
THROTTLE POSITION (TP) SENSOR
Note. Vehicles with Traction Control System (TRAC) are equipped with a main TP sensor and a sub-TP sensor. The following table applies to main TP sensor. For sub-TP sensor table, see SUB-THROTTLE POSITION (SUB-TP) SENSOR.
| Application & Throttle Plate Position (1) | TP Sensor (2) Terminals | Ohm Reading |
|---|
| Throttle Fully Closed | VTA1 & E2 | 340-6300 |
| .016" (.40 mm) (3) | IDL1 & E2 | 500 Or Less |
| Throttle Fully Open | VTA1 & E2 | 2400-11,200 |
| All Positions | VC & E2 | 3100-7200 |
| (1) For terminal identification, see THROTTLE POSITION (TP) SENSOR in ON-VEHICLE ADJUSTMENTS article. (2) Disconnect vacuum hose from throttle opener. Apply vacuum to throttle opener to allow throttle to fully seat. (3) Insert feeler gauge between throttle lever and throttle stop screw. |
| (1) | For terminal identification, see THROTTLE POSITION (TP) SENSOR in ON-VEHICLE ADJUSTMENTS article. |
| (2) | Disconnect vacuum hose from throttle opener. Apply vacuum to throttle opener to allow throttle to fully seat. |
| (3) | Insert feeler gauge between throttle lever and throttle stop screw. |
SUB-THROTTLE POSITION (SUB-TP) SENSOR
Note. Vehicles with Traction Control System (TRAC) are equipped with a main TP sensor and a sub-TP sensor. The following table applies to sub-TP sensor. For main TP sensor table, see THROTTLE POSITION (TP) SENSOR.
| Throttle Plate Position | Sub-TP Sensor Terminals | Ohm Reading |
|---|
| Throttle Fully Closed | VTA1/2 & E2 | 340-6300 |
| .012" (.35 mm) (1) | IDL1/2 & E2 | 500 Or Less |
| .020" (.50 mm) (1) | IDL1/2 & E2 | Infinite (Open) |
| Throttle Fully Open | VTA1/2 & E2 | 2400-11,200 |
| All Positions | VC & E2 | 3100-7200 |
| (1) Remove sub-throttle actuator from throttle body. Insert feeler gauge between end of sub-throttle valve gear and sub-throttle valve stop screw. |
| (1) | Remove sub-throttle actuator from throttle body. Insert feeler gauge between end of sub-throttle valve gear and sub-throttle valve stop screw. |
THROTTLE OPENER
| Application | (1) RPM |
|---|
| LS400 | 1000-1400 |
| (1) Disconnect and plug throttle opener vacuum hose. Specification is with engine at idle and at normal operating temperature. |
| (1) | Disconnect and plug throttle opener vacuum hose. Specification is with engine at idle and at normal operating temperature. |
THROTTLE OPENER SET SPEED SPECIFICATIONS
