ENGINE COMPRESSION
Check engine compression with engine at normal operating temperature, all spark plugs removed and throttle wide open.
| Application | Specification | ||
|---|---|---|---|
| Compression Ratio | |||
| 3.8L | |||
| VIN K | 9.4:1 | ||
| VIN 1 | 8.5:1 | ||
| 4.0L | 10.3:1 | ||
| Normal Compression Pressure | (1) | ||
| Minimum Compression Pressure | (1) | ||
| (1) Lowest compression reading should not be less than 70 percent of highest compression reading. No cylinder compression reading should be less than 100 psi (7 kg/cm 2 ). | |||
| (1) | Lowest compression reading should not be less than 70 percent of highest compression reading. No cylinder compression reading should be less than 100 psi (7 kg/cm 2 ). |
COMPRESSION SPECIFICATIONS
VALVE CLEARANCE
Note. All models are equipped with hydraulic lifters. Adjustment is not required.
HIGH TENSION WIRE RESISTANCE
| Application | Ohms |
|---|---|
| 3.8L & 4.0L | 30,000 Maximum |
HIGH TENSION WIRE RESISTANCE
SPARK PLUGS
| Application | AC Spark Plug | |
|---|---|---|
| 3.8L | ||
| VIN K | 41-921 | |
| VIN 1 | 41-601 | |
| 4.0L | 41-900 | |
SPARK PLUG TYPE
| Application | Gap: In. (mm) | Torque: Ft. Lbs. (N.m) |
|---|---|---|
| 3.8L | .060 (1.52) | 11 (15) |
| 4.0L | .050 (1.27) | 11 (15) |
SPARK PLUG SPECIFICATIONS
Firing Order (3.8L). Scheme 1
Firing Order (4.0L). Scheme 2
IGNITION TIMING
Note. All engines are equipped with C(3)I, DIS, IDI or Opti-Spark ignition system. Timing on these systems is not adjustable.
FUEL PUMP
| Application | Pressure: psi (kg/cm 2 ) |
|---|---|
| 3.8L | 48-55 (3.37-3.87) |
| 4.0L | 46-59 (3.23-4.15) |
FUEL PUMP PERFORMANCE
INJECTOR RESISTANCE
| Application | Ohms |
|---|---|
| 3.8L | (1) 11.4-12.6 |
| 4.0L | (1) 8.0-25.0 |
| (1) Injector resistance specification is at 50-95°F (10-35°C). | |
| (1) | Injector resistance specification is at 50-95°F (10-35°C). |
INJECTOR RESISTANCE SPECIFICATIONS
IDLE SPEED & MIXTURE
Note. Idle mixture is controlled by Powertrain Control Module (PCM). Idle mixture adjustment is neither required nor possible.
THROTTLE POSITION (TP) SENSOR
Note. For further testing, see appropriate TESTS W/CODES article.
| Application | Volts |
|---|---|
| 3.8L & 4.0L | (1) (2) |
| (1) TP sensor is not adjustable. (2) Voltage range is less than one volt at closed throttle to greater than 4 volts at wide open throttle. | |
| (1) | TP sensor is not adjustable. |
| (2) | Voltage range is less than one volt at closed throttle to greater than 4 volts at wide open throttle. |
TP SENSOR ADJUSTMENT VOLTAGE