Compression
Check engine mechanical condition with compression gauge, vacuum gauge, or engine analyzer. See engine analyzer instruction manual for specific instructions.
| CAUTION | Use a remote starter to crank engine during compression test. DO NOT use ignition switch. Fuel injectors on many fuel-injected models are triggered during cranking mode. This could cause a fire hazard, flooding, crankcase contamination, hydrostatic lock, or lubrication to be washed off cylinder walls. |
Measure engine compression at normal operating temperature with all spark plugs removed. To prevent damage to catalytic converter, test quickly and only if necessary.
Note. Compression pressures are not specified by manufacturer.
| Application | Specification |
|---|---|
| 2.0L | 9.2:1 |
COMPRESSION RATIO
Exhaust System Backpressure
The exhaust system can be checked with a vacuum or pressure gauge. If using a pressure gauge, remove oxygen 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, exhaust system or catalytic converter is plugged.
If using a vacuum gauge, 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 SYSTEM
| WARNING | Always relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components. |
FUEL PRESSURE
Begin basic diagnosis of fuel system by measuring system pressure.
- Turn ignition off. Disconnect banjo coupling at inlet to fuel injection manifold. Connect a fuel pressure gauge, using existing seals. Hang pressure gauge vertically.
- Remove fuse No. 32 (15-amp). Connect a fused jumper lead between battery voltage and load side slot of fuse No. 32. This will provide current to fuel pump. Turn ignition on.
- Fuel pressure should increase to about 43 psi (3.0 kg/cm 2 ). If fuel pressure is too high, go to next step. If fuel pressure is too low, go to step 5).
- Turn ignition off. Disconnect fuel return line from pressure regulator. Blow through line. If line is open, pressure regulator is defective and should be replaced. If line is blocked, remove blockage or replace with a new return line. Inspect one-way valve at tank, and retest system.
- Check fuel level; DO NOT rely on fuel gauge. Inspect for fuel system leaks. Test fuel pressure regulator. See «FUEL PRESSURE REGULATOR»(ref-15446-S08508869332000122900000) .
Fuel Pressure Regulator
- If fuel pressure gauge is already attached, go to next step. If gauge is not attached, disconnect banjo coupling at inlet to fuel injection manifold. Connect fuel pressure gauge at this point, using existing seals. Hang pressure gauge vertically.
- Connect Pressure Gauge (83-93-514 ) and "Y" connection to vacuum port of fuel pressure regulator. Hang gauge vertically. Connect pressure/vacuum tester to "Y" connection.
- Remove fuse No. 32 (15-amp). Connect a fused jumper lead between battery voltage and load side slot of fuse No. 32. This will provide current to fuel pump. Turn ignition on.
- Fuel pressure should increase to about 43 psi (3.0 kg/cm 2 ). Install vacuum pump to "Y" connection. Fuel pressure should be about 43 psi (3.0 kg/cm 2 ). Use vacuum pump to reduce system pressures as specified in «REGULATED FUEL PRESSURE (VACUUM APPLIED)»(ref-15446-S25543378492000122900000) table. Compare fuel pressure to specification. Disconnect vacuum pump. REGULATED FUEL PRESSURE (VACUUM APPLIED) Applied Vacuum In. Hg Fuel Pressure psi (kg/cm 2 ) 0 43 (3.0) 5 40.5 (2.9) 10 38 (2.7) 15 35.5 (2.5)
- Increase pressure as specified in «REGULATED FUEL PRESSURE (PRESSURE APPLIED)»(ref-15446-S10449250462000122900000) table. Compare fuel pressure to specification. REGULATED FUEL PRESSURE (PRESSURE APPLIED) Applied Pressure psi (kg/cm 2 ) Fuel Pressure psi (kg/cm 2 ) 0 (0) 43 (3.0) 3.0 (0.2) 46 (3.3) 6.0 (0.4) 49 (3.5) 8.5 (0.6) 51.5 (3.9)
- Turn ignition on to operate fuel pump. Verify fuel pressure is 43 psi (3.0 (3.0 kg/cm 2 ). Turn ignition off. Pressure should drop 1.4-2.8 psi (0.1-0.2 kg/cm 2 ) and then hold steady for at least 10 minutes.
- If pressure drop is more than specified, inspect for leakage in pressure regulator and fuel pump non-return valve.
Fuel Pump Delivery Pressure
- Turn ignition off. Disconnect banjo coupling at inlet to fuel injection manifold. Connect fuel pressure gauge, using existing seals. Hang pressure gauge vertically. Turn ignition on. Pinch off fuel return line. Measure fuel pressure. When line is plugged, fuel pressure should increase immediately. CAUTION: DO NOT allow pressure to exceed 82 psi (5.8 kg/cm 2 ).
- If fuel pressure does not increase, inspect for following faults: Less than 11.5 volts across fuel pump terminals. Obstructed fuel lines. Clogged fuel filter. Fuel filter installed backward. Defective relief valve in fuel pump. NOTE: If fuel filter has been installed backward, it must be replaced.
- After measuring fuel pump pressure, turn ignition off. Leave pressure gauge connected. Go to «FUEL PUMP FLOW»(ref-15446-S19539397732000122900000) .
Fuel Pump Flow
- Turn ignition off. Disconnect fuel return line at pressure regulator. Connect a section of test hose to return line at pressure regulator. Place other end of test hose in 2-quart (approximate) graduated container.
- Activate fuel pump by turning ignition on. Run fuel pump for 30 seconds. Measure volume of fuel flow and fuel pressure drop. Minimum acceptable volume is 1.9 pts. (0.9L); maximum allowed fuel pressure drop is 2.8 psi (0.2 kg/cm 2 ). If fuel volume or pressure drop does not meet specification, replace fuel pressure regulator.
TRIONIC IGNITION SYSTEM
| CAUTION | When performing the following step, position Ignition Coil Module (ICM) with coils and spark plugs downward. |
Note. Ignition Coil Module (ICM) may also be referred to as the Ignition Discharge Module (IDM).
Scheme 29
- Remove Ignition Coil Module (ICM) from cylinder head. Insert spark plug into each spark plug receptacle. Ground spark plugs with Cable (86 10 867 ). Connect scan tool, following manufacturer's instructions.
- Select ACTIVATE. Select IGNITION COILS. ICM will activate for about 10 seconds. Check for spark at each spark plug. Repeat procedure if necessary. If any coil is not operating, go to next step. If all coils are operating, go to step 4).
- Unplug 10-pin ICM connector. Connect one lead of a test light to ICM harness connector terminal No. 10. Connect remaining test light lead alternately to ICM harness connector terminals No. 2, 3, 4 and 5. (Scheme 29) Activate each ignition coil with scan tool. Test light should come on with very short interruptions for about 10 seconds. Repeat procedure for each coil circuit. If test light comes on as specified, replace ICM and retest system. If test light does not come on as specified, go to next step.
- Check wiring between ICM connector and ECM for continuity. See «WIRING DIAGRAMS»(ref-15446-S02863909072000122900000) at the end of this article. If problem is found, repair wiring as necessary. If wiring is good, replace ECM. Retest system.
PROGRAMMING ECM
Note. If power supply to Electronic Control Module (ECM) has been interrupted, system must be reprogrammed.
Drive vehicle for 10 minutes with engine at normal operating temperature.
IDLE SPEED & IGNITION TIMING
For idle speed adjustment, see ADJUSTMENTS - 2.0L TURBO article. Vehicle is equipped with a Distributorless Ignition System (DIS). Ignition timing is controlled by the Electronic Control Module (ECM) and is not adjustable.
SUMMARY
If no faults were found while performing steps in BASIC TESTING , proceed to TESTS W/CODES - 2.0L TURBO article. If no hard codes are found in self-diagnostics, (if vehicle has self-diagnostic system) see TESTS W/O CODES - 2.0L TURBO article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.
