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 mode, 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 |
|---|
| Protege SOHC 1.5L (1) | 146 (10.3) @ 300 | 195 (13.7) @ 300 |
| (1) Maximum difference between cylinders is 28 psi (2.0 kg/cm 2 ). |
| (1) | Maximum difference between cylinders is 28 psi (2.0 kg/cm 2 ). |
COMPRESSION SPECIFICATIONS
Exhaust System Backpressure
The exhaust system can be checked with a vacuum or pressure gauge. Remove O2S sensor 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 1 3/4 - 2 psi (.12-.14 kg/cm 2 ), 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 (FUEL INJECTION)
| WARNING | ALWAYS relieve fuel pressure before disconnecting any fuel injection related component. DO NOT allow fuel to contact engine or electrical components. |
Fuel Pressure
- Disconnect fuel pump relay. See FUEL PUMP RELAY LOCATIONS table. Start engine (if possible) and allow to die. Connect pressure gauge to fuel line at fuel filter. Reconnect fuel pump relay.
- Turn ignition on. Jump engine compartment test connector terminals F/P and GND. If pump does not run, check fuel pump circuit and fuel pump relay. See FUEL PUMP CIRCUIT & RELAY. Start engine. Check fuel pressure with vacuum connected to and disconnected from pressure regulator. See REGULATED FUEL PRESSURE table. Turn engine off.
- Operate fuel pump for 10 seconds. Turn ignition off. Wait 5 minutes. If residual pressure is at least 21 psi (1.5 kg/cm 2 ), go to next step. If residual pressure is not at least 21 psi (1.5 kg/cm 2 ), perform fuel pump maximum pressure test. See next step. Wait 5 minutes and ensure residual pressure is at least 50 psi (3.5 kg/cm 2 ).
- Check fuel pump maximum pressure. Plug fuel pressure gauge outlet. Operate fuel pump. DO NOT operate longer than necessary to check pressure. See FUEL PUMP MAXIMUM PRESSURE table.
- Turn ignition off and disconnect jumper wire at fuel pump check connector. If pump does not meet specifications, check fuel pump circuits, fuel pump, fuel tank and fuel filter. Repair or replace as necessary.
| Application | Pressure |
|---|
| Protege (1) | 72-92 psi (5.0-6.5 kg/cm 2 ) |
| (1) Information is not available from manufacturer. |
| (1) | Information is not available from manufacturer. |
FUEL PUMP MAXIMUM PRESSURE
| Application | At Idle W/ Vacuum psi (kg/cm 2 ) | At Idle W/O Vacuum psi (kg/cm 2 ) |
|---|
| Protege | 27-34 (2.0-2.4) | 40-45 (2.8-3.2) |
Fuel Pump Circuit & Relay
- Turn ignition on. Attach jumper wire between test connector terminals F/P and GND in the diagnostic connector, next to battery. Listen for fuel pump operating sound. If there is no sound, check 10-amp ENGINE fuse, 30-amp FUEL INJ fuse, main relay, fuel pump relay and all electrical connections.
- Disconnect fuel pump connector. Check continuity between fuel pump battery positive and ground terminals. See FUEL PUMP CONNECTOR WIRE IDENTIFICATION table. If continuity exists, go to next step. If continuity does not exist, replace fuel pump.
- Measure voltage at fuel pump connector battery positive terminal. See FUEL PUMP CONNECTOR WIRE IDENTIFICATION table. If battery voltage exists, go to next step. If battery voltage does not exist, go to step 5).
- Measure resistance of fuel pump ground wire (Black wire) to chassis ground. If resistance is less than one ohm, go to next step. If resistance is not less than one ohm, repair open in Black wire between fuel pump and ground.
- With relay connected, ensure battery voltage is present at relay terminal White/Red wire. For locations of fuel pump relay, see FUEL PUMP RELAY LOCATIONS table.
- If voltages are okay, remove relay from vehicle. Using a 12-volt battery source, connect 12 volts to relay terminals "A" and ground terminal "B". Ensure continuity is present across terminals "C" and "E". (Scheme 5) If continuity is not as specified, replace fuel pump relay.
| Application | Location |
|---|
| Protege | Passenger Side Of Front Console, Near PCM |
FUEL PUMP RELAY LOCATIONS
| Application | Battery Positive | Ground |
|---|
| Protege | Black/Pink | Black |
FUEL PUMP CONNECTOR WIRE IDENTIFICATION
Scheme 5
SPARK CHECK
Check for spark at coil wire and at each spark plug wire using a high output spark tester. Check spark plug wire resistance on suspect wires. Resistance should be 4878 ohms per foot.
IGNITION COIL POWER SOURCE
Turn ignition on. Using voltmeter, check for 12 volts between positive (+) terminal and ground. If no voltage is present, check battery feed, main fuse, ignition switch and fusible links.
IGNITION COIL RESISTANCE
- Remove primary and secondary leads from ignition coil. Using ohmmeter, check primary resistance between positive and negative terminals of coil. (Scheme 6) Resistance should be as specified in IGNITION COIL RESISTANCE table. If resistance is not as specified, replace ignition coil.
- Check secondary resistance between coil towers of each coil. (Scheme 7) See IGNITION COIL RESISTANCE table. If resistance is not within specification, replace coil.
- Check insulation resistance of case. Using a 500-volt meter, measure insulation resistance between positive terminal and coil case. If resistance is not more than 10 megohms, replace ignition coil.
Scheme 6
Scheme 7
| Application | Primary | Secondary |
|---|
| Protege (1) | .49-.73 | 20,000-31,000 |
| (1) Remove distributor cap to measure secondary coil resistance. |
| (1) | Remove distributor cap to measure secondary coil resistance. |
CRANKSHAFT POSITION SENSOR RESISTANCE
- Disconnect crankshaft position sensor connector. Crankshaft position sensor is a separate unit located at front of crankshaft. Measure resistance between terminals. See CRANKSHAFT POSITION SENSOR RESISTANCE table. (Scheme 8) If resistance is not as indicated, replace crankshaft position sensor.
- If ignition coil resistance and crankshaft position sensor test okay, check for spark. If spark is still not present, go to appropriate HALL EFFECT SENSOR procedure.
| Application | Ohms | Air Gap In. (mm) |
|---|
| Protege | 500-600 | .20-.59 (0.5-1.5) |
CRANKSHAFT POSITION SENSOR RESISTANCE
Scheme 8
HALL EFFECT SENSORS
- Remove distributor. Remove fuel pump relay and disconnect 3-pin or 4-pin connector from distributor. This will prevent coil sparking. Turn ignition on.
- Using a voltmeter, backprobe power wire and ground wire at distributor. Voltmeter should display 12 volts. If voltage is not as specified, check ignition and ground circuits. Backprobe sensor wire at distributor. See HALL EFFECT SENSOR VOLTAGE SPECIFICATIONS table. Slowly rotate distributor shaft one turn. Voltmeter should pulse 0-5 volts 4 times (4-cylinder) or 6 times (V6).
- Backprobe sensor wire at distributor. See HALL EFFECT SENSOR VOLTAGE SPECIFICATIONS table. Slowly rotate distributor shaft one turn. Voltmeter should pulse 0-5 volts one time. If either sensor does not work as described, turn ignition off. Disconnect 6-pin connector at distributor.
- Turn ignition on. Ensure 5 volts are present at same wires which were checked in steps 2) and 3). If 5 volts are not present, check wiring and PCM. If 5 volts are present, replace distributor assembly.
| Wire Color | Volts |
|---|
| Black/White (Power) | 12 |
| Green/White (Sensor) | (1) 0-5 |
| Blue (Sensor) | (1) 0-5 |
| Black (Ground) | 0 |
| (1) Voltage should fluctuate from 0-5 volts as engine is turned slowly. |
| (1) | Voltage should fluctuate from 0-5 volts as engine is turned slowly. |
HALL EFFECT SENSOR VOLTAGE SPECIFICATIONS
IGNITION CONTROL MODULE (PROTEGE)
Check ignition coil, PCM and high tension lead connections. Check secondary coil winding and high tension lead resistance. Measure voltage at appropriate PCM terminals. See PCM TERMINAL IDENTIFICATION table. If all measurements are within specification, and misfire still occurs, replace distributor or ignition coil.
| Wire Color To Ground (1) | KOEO Volts | KOER (Idle) Volts |
|---|
| Yellow/Violet (4N) | Below 1 | 0.3 |
| Violet/Green (4F) | 0 Or 5 | 2 |
| Violet/Red (4G) | 0 Or 5 | 2.5 |
| (1) PCM terminal number in parentheses. |
| (1) | PCM terminal number in parentheses. |
PCM TERMINAL IDENTIFICATION
IDLE SPEED & IGNITION TIMING
Ensure idle speed and base ignition timing are set to specification. See IDLE SPEED SPECIFICATIONS and IGNITION TIMING SPECIFICATIONS tables. If necessary, see ADJUSTMENTS - 1.5L article.
| Application | M/T RPM | (1) A/T RPM |
|---|
| Protege 1.5L (2) | 700 | 750 |
| (1) Place automatic transmission in Park. (2) Connect jumper wire between terminals TEN and GRD of data link connector. |
| (1) | Place automatic transmission in Park. |
| (2) | Connect jumper wire between terminals TEN and GRD of data link connector. |
IDLE SPEED SPECIFICATIONS
| Application | M/T | (1) A/T |
|---|
| 1.5L (2) | 10 @ 700 | 10 @ 750 |
| (1) Place automatic transmission in Park. (2) Connect jumper wire between terminals TEN and GRD of data link connector. |
| (1) | Place automatic transmission in Park. |
| (2) | Connect jumper wire between terminals TEN and GRD of data link connector. |
IGNITION TIMING SPECIFICATIONS
SUMMARY
If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to appropriate TESTS W/CODES - 1.5L article. If no hard codes are found in TESTS W/CODES , proceed to appropriate TESTS W/O CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.
