Compression
Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. See engine analyzer manual for specific instructions.
| WARNING | DO NOT use ignition switch during compression tests on fuel injected vehicles. Use a remote starter to crank engine. Fuel injectors on many models are triggered by ignition switch during cranking, which can create a fire hazard or contaminate the engine's oiling system. |
| Application | Minimum psi (kg/cm 2 ) @ RPM | Standard psi (kg/cm 2 ) @ RPM |
|---|---|---|
| Millenia 2.3L (1) | 142 (10.0) @ 300 | 185 (13.0) @ 300 |
| (1) Difference between cylinders should not be more than 28 psi (2.0 kg/cm 2 ). | ||
| (1) | Difference between cylinders should not be more than 28 psi (2.0 kg/cm 2 ). |
COMPRESSION SPECIFICATIONS
Exhaust System Backpressure
Exhaust system can be checked with a vacuum or pressure gauge. Remove Heated Oxygen Sensor (HO2S) or air injection check valve (if equipped). Connect a 0-5 psi pressure gauge and run engine at 2500 RPM. If exhaust system backpressure is greater than 2 psi, exhaust system or catalytic converter is plugged.
If a vacuum gauge is used, connect vacuum gauge hose to intake manifold vacuum port and start engine. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge reading slowly drops after stabilizing, exhaust system should be checked for a restriction.
FUEL PRESSURE RELEASE
Disconnect fuel pump relay. See FUEL PUMP RELAY LOCATIONS table. Start engine (if possible) and allow to die. Turn ignition off.
| Application | Location |
|---|---|
| Millenia 2.3L | In Left Rear Of Engine Bay, Mounted Near Cruise Actuator |
FUEL PUMP RELAY LOCATIONS
Fuel Pressure Hold
- Disconnect negative battery cable. Install fuel pressure gauge in fuel supply line. Reconnect negative battery cable.
- Locate data link connector in left side of engine compartment. Connect a jumper wire between data link connector terminals F/P and GND. (Scheme 71) Turn ignition on for 10 seconds to operate fuel pump. Turn ignition off and disconnect jumper wire. Wait 5 minutes and observe fuel pressure. Fuel pressure should be at least 21 psi (1.5 kg/cm 2 ).
- If fuel pressure is not as specified, check fuel pump hold pressure and fuel pressure regulator hold pressure. See FUEL PUMP HOLD PRESSURE and FUEL PRESSURE REGULATOR HOLD PRESSURE headings below. Also check for injector fuel leakage. See INJECTOR FUEL LEAKAGE heading below.
Scheme 71
Fuel Line Pressure
- Disconnect negative battery cable. Install fuel pressure gauge in fuel supply line. Reconnect negative battery cable. Locate data link connector in left side of engine compartment. Connect a jumper wire between data link connector terminals F/P and GND. (Scheme 71) Turn ignition on and observe fuel line pressure. Refer to the «FUEL LINE PRESSURE»(ref-18720-S37400336682000123000000) table.
- If fuel line pressure is high, replace fuel pressure regulator. If fuel line pressure is low, check fuel pump maximum pressure. See FUEL PUMP MAXIMUM PRESSURE heading below. If fuel pump maximum pressure is as specified, check for plugged or restricted fuel line or fuel filter. Repair as necessary. If no problems are found, check pressure regulator hold pressure. See PRESSURE REGULATOR HOLD PRESSURE heading below.
| Application | Pressure psi (kg/cm 2 ) |
|---|---|
| Millenia 2.3L | 38-48 (2.7-3.4) |
FUEL LINE PRESSURE
Fuel Pump
- Fuel pump is located inside fuel tank. Locate data link connector in left side of engine compartment. Connect a jumper wire between data link connector terminals F/P and GND. (Scheme 71) Remove fuel filler cap. Turn ignition on. Listen for fuel pump operation at fuel filler. Install fuel filler cap.
- If fuel pump does not operate, using DVOM, measure voltage between fuel pump connector power terminal and chassis ground. See «FUEL PUMP CONNECTOR IDENTIFICATION»(ref-18720-S19479904402000123000000) table. If battery voltage is present, go to next step. If battery voltage is not present, repair power circuit to fuel pump. See appropriate wiring diagram in «WIRING DIAGRAMS - 2.3L»(ref-18690) article.
- Using DVOM, check for continuity between fuel pump connector ground terminal and chassis ground. If continuity exists, replace fuel pump. If continuity does not exist, repair ground circuit.
| Application | Power Terminal | Ground Terminal |
|---|---|---|
| Millenia | Yellow | Black |
FUEL PUMP CONNECTOR IDENTIFICATION
Fuel Pump Hold Pressure
- Disconnect negative battery cable. Disconnect fuel inlet hose at fuel rail. Install fuel pressure gauge to fuel inlet hose and plug fuel pressure gauge outlet hose. Reconnect negative battery cable.
- Locate data link connector in left side of engine compartment. Connect a jumper wire between data link connector terminals F/P and GND. (Scheme 71) Turn ignition on for 10 seconds to operate fuel pump. Turn ignition off and disconnect jumper wire. Wait 5 minutes and observe fuel pressure. Fuel pressure should be at least 21 psi (1.5 kg/cm 2 ). If fuel pressure is not as specified, replace fuel pump.
Fuel Pump Maximum Pressure
- Disconnect negative battery cable. Disconnect fuel inlet hose at fuel rail. Install fuel pressure gauge to fuel inlet hose and plug fuel pressure gauge outlet hose. Reconnect negative battery cable.
- Locate data link connector in left side of engine compartment. Connect a jumper wire between data link connector terminals F/P and GND. (Scheme 71) Turn ignition on for 10 seconds to operate fuel pump and observe fuel pressure. See «FUEL PUMP MAXIMUM PRESSURE»(ref-18720-S22314896562000123000000) table. Turn ignition off and disconnect jumper wire. If fuel pressure is not as specified, replace fuel pump.
| Application | Pressure psi (kg/cm 2 ) |
|---|---|
| Millenia 2.3L | 91-117 (6.4-8.2) |
FUEL PUMP MAXIMUM PRESSURE
Fuel Pump Relay
- Locate fuel pump relay. See «FUEL PUMP RELAY LOCATIONS»(ref-18720-S19727849882000123000000) table under FUEL PRESSURE RELEASE. Using jumper wires, connect battery voltage to fuel pump relay terminal "A" (positive) and terminal "B" (negative). (Scheme 72)
- Check continuity between fuel pump relay terminals "C" and "D". With battery voltage connected, continuity should exist. With battery voltage disconnected, continuity should not exist. If continuity is not as specified, replace fuel pump relay.
Scheme 72
Fuel Pressure Regulator
- Disconnect negative battery cable. Install fuel pressure gauge in fuel supply line. Reconnect negative battery cable.
- Start and operate engine at idle. Ensure vacuum is available to pressure regulator. Observe fuel pressure with vacuum hose connected and disconnected at fuel pressure regulator. See «REGULATED FUEL PRESSURE»(ref-18720-S15789340832000123000000) table. If fuel pressure is not as specified, check fuel pressure regulator hold pressure. See FUEL PRESSURE REGULATOR HOLD PRESSURE heading below.
| Model | @ Idle W/Vacuum psi (kg/cm 2 ) | @ Idle W/O Vacuum psi (kg/cm 2 ) |
|---|---|---|
| Millenia 2.3L | 30-41 (2.1-2.9) | 38-48 (2.7-3.4) |
REGULATED FUEL PRESSURE
Fuel Pressure Regulator Hold Pressure
- Disconnect negative battery cable. Install fuel pressure gauge in fuel supply line. Reconnect negative battery cable.
- Locate data link connector in left side of engine compartment. Connect a jumper wire between data link connector terminals F/P and GND. (Scheme 71)Turn ignition on for 10 seconds to operate fuel pump. Turn ignition off and disconnect jumper wire. Carefully pinch fuel return hose close. Wait 5 minutes and observe fuel pressure.
- Fuel pressure should be more than 21 psi (1.5 kg/cm 2 ). If fuel pressure is not as specified, replace fuel pressure regulator.
Injector Fuel Leakage
- Using mechanics wire, secure each fuel injector to fuel rail. Disconnect fuel injector connectors. Remove fuel rail assembly from intake manifold. See appropriate engines article in the ENGINES section. Reconnect fuel lines to fuel rail. Locate data link connector in left side of engine compartment.
- Connect a jumper wire between data link connector terminals F/P and GND. (Scheme 71) Turn ignition on. Tilt injectors about 60 degrees and check injector nozzles for fuel leaks. Fuel leakage should be less than one drop every 2 minutes. If fuel leakage exists, replace injector.
SPARK CHECK
Remove spark plug. Connect spark plug to high-tension lead and hold about 1/4" from ground. Crank engine and verify a strong Blue spark is discharged. If spark is not present, measure spark plug wire resistance on suspect wire. Resistance should be less than 16,000 ohms per 3.28 feet. Replace spark plug wire and spark plug as necessary.
IGNITION COIL POWER SOURCE
Turn ignition on. Using voltmeter, check for 12 volts between ignition coil positive (+) terminal and ground. If voltage is not present, check battery feed, main fuse, ignition switch and fusible links. See appropriate wiring diagram in WIRING DIAGRAMS - 2.3L article.
IGNITION COIL RESISTANCE
Ignition coil and ignition control module are integrated as a coil-on-plug unit. Ignition coil testing procedure and resistance specifications are not available from manufacturer. If misfire DTC is present (DTC's P0300-P0306), refer to appropriate Self-Diagnostics article to retrieve codes and diagnose misfire. Misfire diagnostic procedure includes switching ignition coil with a known good ignition coil from another cylinder.
CRANKSHAFT POSITION SENSOR RESISTANCE
Disconnect crankshaft position sensor connector. Using ohmmeter, measure resistance between terminals "A" and "B". (Scheme 73) Resistance should be as specified. Refer to the CRANKSHAFT POSITION SENSOR RESISTANCE table. If resistance is not as specified, replace crankshaft position sensor.
| Application | Ohms@ 68°F (20°C) |
|---|---|
| Millenia 2.3L | 950-1250 |
CRANKSHAFT POSITION SENSOR RESISTANCE
Scheme 73
CRANKSHAFT POSITION SENSOR AIR GAP
Using a feeler gauge, measure air gap between crankshaft pulley and crankshaft position sensor. (Scheme 74) Air gap should be as specified. See CRANKSHAFT POSITION SENSOR AIR GAP table. If air gap is not as specified, replace crankshaft pulley or crankshaft position sensor.
| Application | In. (mm) |
|---|---|
| Millenia 2.3L | .040-.080 (1.0-2.0) |
CRANKSHAFT POSITION SENSOR AIR GAP
Scheme 74
CAMSHAFT POSITION SENSOR VOLTAGE
- Remove camshaft position sensor and reconnect connector. Disconnect ignition control module connector. Disconnect fuel injector connector. Turn ignition on. Connect Harness Adapter (49 T018 902) and Signal Monitor (49 9200 162A) to ECM. (Scheme 75)
- Set signal monitor to specified ECM terminal. Rotate camshaft position sensor by hand and measure output voltage. See the «CAMSHAFT POSITION SENSOR VOLTAGE»(ref-18720-S28047944352000123000000) table. If voltage is not as specified, check wiring harness and connectors. If harness and connectors are okay, replace camshaft position sensor.
| ECM/PCM Terminal (1) | (2) Volts |
|---|---|
| Millenia 4F (SGC Signal) | 5 (1 pulses/rev) |
| (1) See PIN VOLTAGE/PID VALUE CHARTS - 2.3L article for terminal identification. (2) Rotate sensor/distributor by hand while measuring output voltage. | |
| (1) | See PIN VOLTAGE/PID VALUE CHARTS - 2.3L article for terminal identification. |
| (2) | Rotate sensor/distributor by hand while measuring output voltage. |
CAMSHAFT POSITION SENSOR VOLTAGE
Scheme 75
IGNITION CONTROL MODULE
Testing information is not available from manufacturer. Check for diagnostic trouble codes. See appropriate TESTS W/CODES - 2.3L article.
IDLE SPEED & IGNITION TIMING
Ensure idle speed and base ignition timing are set to specification. See the appropriate IDLE SPEED SPECIFICATIONS and IGNITION TIMING SPECIFICATIONS tables. If adjustment is necessary, see ADJUSTMENTS - 2.3L article.
| Application (2) | M/T RPM | (1) A/T RPM |
|---|---|---|
| Millenia | N/A | 600-700 |
| (1) Connect a jumper wire between terminals TEN and GND at data link connector. (Scheme 71) (2) Place automatic transmission in Park. | ||
| (1) | Connect a jumper wire between terminals TEN and GND at data link connector. (Scheme 71) |
| (2) | Place automatic transmission in Park. |
IDLE SPEED SPECIFICATIONS
| Application | M/T | (1) A/T |
|---|---|---|
| Millenia 2,3L (2) | N/A | 6-8 @ 650 |
| (1) Place automatic transmission in Park. (2) Connect a jumper wire between terminals TEN and GND of data link connector. (Scheme 71) | ||
| (1) | Place automatic transmission in Park. |
| (2) | Connect a jumper wire between terminals TEN and GND of data link connector. (Scheme 71) |
IGNITION TIMING SPECIFICATIONS (Degrees BTDC @ RPM)
SUMMARY
If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to appropriate TESTS W/CODES - 2.3L article. If no hard codes are found in self-diagnostics, proceed to TESTS W/O CODES - 2.3L article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.