Compression
Warm engine to normal operating temperature before checking the compression. Check engine mechanical condition with a compression gauge, vacuum gauge, or engine analyzer. See engine analyzer manual for specific instructions. See COMPRESSION SPECIFICATIONS table.
| WARNING | DO NOT use ignition switch during compression tests. 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 | Specification |
|---|---|
| Normal 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
Exhaust System Backpressure
- The exhaust system can be checked with a vacuum or pressure gauge. Remove HO2S sensor or air injection check valve (if equipped).
- Connect a 1-5 psi pressure gauge and operate 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 to intake manifold vacuum port and start engine. Observe vacuum gauge. Open throttle part way and hold it steady. If vacuum gauge reading slowly drops after stabilizing, check exhaust system for restriction.
FUEL SYSTEM
Basic diagnosis of fuel system should begin by checking fuel pump operation and fuel pressure.
| WARNING | ALWAYS relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components. |
FUEL PRESSURE
Note. Vehicles use in-tank fuel pump.
- Ensure battery is fully charged and ignition is off. Disconnect negative battery cable.
- Note location for fuel pressure gauge installation. (Scheme 42) Fuel pressure gauge may be installed on fuel filter or on delivery pipe depending on model application.
- Place container under fuel filter or delivery pipe. Cover union bolt with shop towel. Slowly loosen union bolt to release fuel pressure.
- Remove union bolt and gaskets. Install Fuel Pressure Gauge (SST 09268-45012) using NEW gaskets. (Scheme 42) Tighten union bolt. Reconnect negative battery cable.
- Remove cover (if equipped) and install scan tool on data link connector No. 3. see scheme 1 Turn ignition on. DO NOT start engine.
- Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump and note fuel pressure. Fuel pressure should be within specification. See «FUEL PUMP PERFORMANCE»(ref-22327-S23297070772001010300000) table. NOTE: Fuel pump may also be activated by connecting battery voltage to specified terminals on fuel pump. see scheme 2
- If fuel pressure exceeds specification, replace fuel pressure regulator. Fuel pressure regulator is located on the delivery pipe. If fuel pressure is less than specified, check for defective fuel lines, connections, fuel pump, fuel filter or fuel pressure regulator.
- Turn ignition off. Remove scan tool from data link connector No. 3. Reinstall cover (if equipped). Start engine and allow engine to idle.
- Disconnect and plug vacuum line at fuel pressure regulator. Note fuel pressure. Fuel pressure should be within specification. See «REGULATED FUEL PRESSURE»(ref-22327-S19193984162001010300000) table.
- Reconnect vacuum hose on fuel pressure regulator and note fuel pressure with engine idling. Fuel pressure should be within specification. See «REGULATED FUEL PRESSURE»(ref-22327-S19193984162001010300000) table.
- If fuel pressure is not within specification, check for defective vacuum hose or fuel pressure regulator. Shut engine off and note fuel pressure.
- Fuel pressure should hold at least 21 psi (1.5 kg/cm 2 ) for a minimum of 5 minutes. If fuel pressure does not hold as specified, check for defective fuel pump, fuel injector or fuel pressure regulator.
- Disconnect negative battery cable. Remove fuel pressure gauge. Reinstall union bolt using NEW gaskets. Tighten union bolt. Install negative battery cable. Recheck for fuel leaks.
Scheme 42
Note. For more information on checking fuel injectors and other fuel sub-systems, see SYSTEM/COMPONENT TESTS - 2.2L article.
| Application | Pressure psi (kg/cm 2 ) |
|---|---|
| 2.2L | (1) 38-44 (2.7-3.1) |
| (1) Check fuel pressure with engine off and using scan tool connected to data link connector No. 3 with ignition on to activate fuel pump or by connecting battery voltage to terminals on electric fuel pump. | |
| (1) | Check fuel pressure with engine off and using scan tool connected to data link connector No. 3 with ignition on to activate fuel pump or by connecting battery voltage to terminals on electric fuel pump. |
FUEL PUMP PERFORMANCE
| Application Type Tested | At Idle W/Vacuum psi (kg/cm 2 ) | At Idle W/O Vacuum psi (kg/cm 2 ) |
|---|---|---|
| 2.2L | 33-38 (2.3-2.7) | 38-44 (2.7-3.1) |
REGULATED FUEL PRESSURE
FUEL PUMP CONTROL CIRCUIT
Note. For information on testing relays and fuel system components, see SYSTEM/COMPONENT TESTS - 2.2L article. Relays may be identified by appropriate illustration in THEORY/OPERATION - 2.2L article. Vehicles are equipped with different combinations of fuel system electrical components. For complete wiring circuit of electrical components on a specific model, see appropriate wiring diagram in WIRING DIAGRAMS - 2.2L article.
Note. EFI main relay may also be referred to as EFI relay.
EFI Main Relay
The EFI fuse supplies constant battery voltage to EFI main relay. When ignition is turned on, voltage is supplied through IGN fuse to EFI main relay. EFI main relay is then energized and provides battery voltage to circuit opening relay, data link connector No. 1 and various other electrical components. The EFI main relay also provides battery voltage to +B terminal of Engine Control Module (ECM) when ignition is turned on.
Circuit Opening Relay
Circuit opening relay controls the fuel pump circuit. When EFI main relay is energized, EFI main relay provides battery voltage to one side of circuit opening relay. When engine is cranking, circuit opening relay receives a start signal which energizes circuit opening relay. Circuit opening relay then provides voltage to fuel pump for fuel pump operation. When start signal is released from circuit opening relay, the Engine Control Module (ECM) then controls the ground circuit for circuit opening relay at ECM terminal FC. Circuit opening relay then provides voltage to fuel pump for fuel pump operation.
CRANKSHAFT POSITION SENSOR RESISTANCE
- Crankshaft position sensor is located behind timing belt cover, near crankshaft sprocket. Disconnect electrical connector for crankshaft position sensor, located near generator. (Scheme 43)
- Using ohmmeter, check resistance between terminals on crankshaft position sensor. Replace crankshaft position sensor if resistance is not within specification. See «DISTRIBUTOR TYPE IGNITION SYSTEM CRANKSHAFT POSITION SENSOR RESISTANCE»(ref-22327-S15087293592001010300000) table. Reinstall electrical connector.
| Application | Ohms |
|---|---|
| Cold (1) | 985-1600 |
| Hot (2) | 1265-1890 |
| (1) Cold is with temperature of 14-122°F (-10-50°C). (2) Hot is with temperature of 122-212°F (50-100°C). | |
| (1) | Cold is with temperature of 14-122°F (-10-50°C). |
| (2) | Hot is with temperature of 122-212°F (50-100°C). |
DISTRIBUTOR TYPE IGNITION SYSTEM CRANKSHAFT POSITION SENSOR RESISTANCE
Scheme 43
IGNITION COIL RESISTANCE (DISTRIBUTOR TYPE IGNITION SYSTEM)
- Disconnect wiring from ignition coil so ignition coil is isolated from the system. Using an ohmmeter, check ignition coil primary resistance between ignition coil positive (+) and negative (-) terminals. (Scheme 44)
- Check ignition coil secondary resistance between ignition coil positive (+) terminal and high tension terminal (coil wire tower). (Scheme 45) Replace ignition coil if resistance is not within specification. See «DISTRIBUTOR TYPE IGNITION SYSTEM IGNITION COIL RESISTANCE»(ref-22327-S22763929142001010300000) table.
| Application | Primary | Secondary |
|---|---|---|
| Cold (1) | .36-.55 | 9000-15,400 |
| Hot (2) | .45-.65 | 11,400-18,100 |
| (1) Cold is with temperature of 14-122°F (-10-50°C). (2) Hot is with temperature of 122-212°F (50-100°C). | ||
| (1) | Cold is with temperature of 14-122°F (-10-50°C). |
| (2) | Hot is with temperature of 122-212°F (50-100°C). |
DISTRIBUTOR TYPE IGNITION SYSTEM IGNITION COIL RESISTANCE - Ohms
Scheme 44
Scheme 45
PICK-UP COIL RESISTANCE
Disconnect electrical connector on distributor. Using ohmmeter, check resistance between terminals on distributor for pick-up coil. (Scheme 46) Replace distributor assembly if pick-up coil resistance is not within specification. See PICK-UP COIL RESISTANCE SPECIFICATIONS table. Reinstall electrical connector.
| Application | Pick-Up Coil Terminals | Ohms |
|---|---|---|
| Cold (1) | (3) | 135-220 |
| Hot (2) | (3) | 175-255 |
| (1) Cold is with temperature of 14-122°F (-10-50°C). (2) Hot is with temperature of 122-212°F (50-100°C). (3) Measure resistance between terminals on pick-up coil. | ||
| (1) | Cold is with temperature of 14-122°F (-10-50°C). |
| (2) | Hot is with temperature of 122-212°F (50-100°C). |
| (3) | Measure resistance between terminals on pick-up coil. |
PICK-UP COIL RESISTANCE SPECIFICATIONS
Scheme 46
PICK-UP COIL AIR GAP
- Remove distributor cap. Using non-magnetic feeler gauge, check pick-up coil air gap between signal rotor and pick-up coil projection. (Scheme 47)
- Replace distributor assembly if pick-up coil air gap is not within specification. See «PICK-UP COIL AIR GAP SPECIFICATIONS»(ref-22327-S08920281082001010300000) table.
| Application | In. (mm) |
|---|---|
| 2.2L | .008-.018 (.20-.45) |
PICK-UP COIL AIR GAP SPECIFICATIONS
Scheme 47
IDLE SPEED & IGNITION TIMING
Ensure idle speed and ignition timing are set to specification. For adjustment procedures, see ADJUSTMENTS - 2.2L article.
SUMMARY
If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to self-diagnostics in TESTS W/CODES - 2.2L article. If no hard diagnostic trouble codes are found in self-diagnostics, proceed to TESTS W/O CODES - 2.2L article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.