Engine Controls - System/component Tests - Eec (1.8L): Other Mercury Tracer I

Intake Manifold Control Shutter Valve(s)

Disconnect vacuum hose from shutter valve vacuum actuator. Using vacuum tester, apply vacuum to actuator. If shutter valve linkage is drawn into actuator, actuator and shutter valve are okay. If linkage does not move, check for stuck shutter valve or ruptured diaphragm in actuator.

Vacuum Control Solenoids

Remove solenoid. With no power to solenoid, air should be able to flow between port "B" and "C" (vent). (Scheme 117) Using vacuum tester apply vacuum to port "A", vacuum should hold.

Testing Shutter Valve Vacuum Control Solenoid. Scheme 117

Apply battery voltage to solenoid. (Scheme 117) Air should be able to flow between port "A" and "B" only. If solenoid does not test as specified, replace solenoid.

POWERTRAIN CONTROL MODULE (PCM)

To check PCM ground and power circuits, refer to CIRCUIT TEST PGC in the TESTS W/CODES - EEC (1.8L) article.

BAROMETRIC PRESSURE (BARO) SENSOR

BARO sensor is located inside PCM and cannot be serviced separately. Faults in BARO sensor should set a fault code in PCM memory. See appropriate CIRCUIT TEST BARO in the TESTS W/CODES - EEC (1.8L) article.

CAMSHAFT POSITION (CMP) SENSOR

CMP sensor is located inside distributor and is integrated with CKP sensor. Faults in CMP sensor should set fault code in PCM memory. Distributor is not serviceable. See CIRCUIT TEST CMP in the TESTS W/CODES - EEC (1.8L) article.

CRANKSHAFT POSITION (CKP) SENSOR

CKP sensor is located inside distributor. Faults in CKP sensor should set fault code in PCM memory. See circuit tests CKP1 and CKP2 in the TESTS W/CODES - EEC (1.8L) article.

ENGINE COOLANT TEMPERATURE (ECT) SENSOR

Disconnect ECT sensor wiring harness connector. Using DVOM, measure resistance between sensor terminals at specified temperature. See ECT SENSOR SPECIFICATIONS table. Replace sensor if resistance is not as specified.

ECT SENSOR SPECIFICATIONS

INERTIA FUEL SHUTOFF (IFS) SWITCH

1. Turn ignition off. Remove IFS switch. IFS switch is located inside of trunk area below left side of floor mat. Strike inertia switch to force switch into tripped position (switch open). Measure resistance between IFS switch terminals that connect to Blue and Black wires.
2. With IFS switch open (tripped), resistance should be more than 10,000 ohms. With IFS switch closed (set), resistance should be less than 5 ohms. If IFS switch does not test as specified, replace switch.

INTAKE AIR TEMPERATURE (IAT) SENSOR

Faults in IAT sensor should set fault code in PCM memory. See CIRCUIT TEST IAT in the TESTS W/CODES - EEC (1.8L) article.

THROTTLE POSITION (TP) SENSOR

For throttle position sensor specifications and adjustment procedures, see ADJUSTMENTS - 1.8L article. For circuit testing, see CIRCUIT TEST TP in the TESTS W/CODES - EEC (1.8L) article.

PARK/NEUTRAL POSITION (PNP) SWITCH

For diagnostic procedure, see CIRCUIT TEST STG in the TESTS W/CODES - EEC (1.8L) article.

POWER STEERING PRESSURE (PSP) SWITCH

For diagnostic procedure, see CIRCUIT TEST STG in the TESTS W/CODES - EEC (1.8L) article.

VEHICLE SPEED SENSOR (VSS)

Faults in vehicle speed sensor should set fault code in PCM memory. See CIRCUIT TEST VSS in the TESTS W/CODES - EEC (1.8L) article.

EVAP CANISTER PURGE SOLENOID

Disconnect vacuum and electrical connections from solenoid. Apply low air pressure to port "A" of solenoid and ensure air pressure does not flow from port "B" of solenoid. (Scheme 118) Using jumper wires, connect negative terminal to ground and apply 12 volts to positive terminal. Apply low air pressure to solenoid port "A" and ensure air flows through port "B" of solenoid. Replace solenoid if it does not test as specified.

HIGH SPEED INLET AIR (HSIA) SOLENOID

See VACUUM CONTROL SOLENOIDS under AIR INDUCTION SYSTEMS in this article.

IDLE AIR CONTROL (IAC) SOLENOID

Faults in IAC solenoid should set fault code in PCM memory. For diagnostic procedure, see CIRCUIT TEST SCG in the TESTS W/CODES - EEC (1.8L) article.

Identifying Canister Purge Solenoid. Scheme 118

VARIABLE RESONANCE INDUCTION SYSTEM (VRIS) SOLENOIDS

See VACUUM CONTROL SOLENOIDS under AIR INDUCTION SYSTEMS.

FUEL PRESSURE RELEASE

Depress retaining clips and remove rear seat cushion. Disconnect fuel pump connections. Start engine and operate it until it stalls. Turn ignition off. Reconnect fuel pump. Install rear seat cushion.

Fuel Pressure Check

Release fuel pressure. See FUEL PRESSURE RELEASE. Install Fuel Pressure Gauge (014-00748) between fuel filter and fuel rail. Ensure pressure gauge drain valve is closed and main valve is open. Using jumper wire, connect Data Link Connector (DLC) fuel pump terminal to ground terminal. (Scheme 119) Turn ignition on, but do not start engine. Observe gauge reading. Compare gauge reading. For 1995 fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article. For 1996 fuel pressure specifications, see FUEL PRESSURE SPECIFICATIONS article. Proceed as follows

1. If fuel pressure is zero, go to appropriate NO FUEL PRESSURE.
2. If fuel pressure is low, go to LOW FUEL PRESSURE.
3. If fuel pressure is high, go to HIGH FUEL PRESSURE.
4. If fuel pressure is normal, go to FUEL INJECTOR TEST.

Identifying DLC Terminals. Scheme 119

Scheme 120

1. Turn ignition off. Check if Inertia Fuel Shutoff (IFS) switch has been tripped. IFS switch is mounted on right rear strut tower in luggage area (behind trim panel). Reset IFS switch if tripped. Repeat «FUEL PRESSURE CHECK»(ref-23202-S01732483132001010300000). If IFS switch is not tripped go to next step.
2. Remove fuel pump relay. Relay is located forward of center console. Measure resistance of Light Green wire between fuel pump relay connector and fuel pump test terminal at Data Link Connector (DLC). (Scheme 119) If resistance is less than 5 ohms, reinstall fuel pump relay and go to next step. If resistance is greater than 5 ohms, service Light Green wire between DLC and fuel pump relay connector.
3. Turn Ignition off. Using a jumper wire, ground the fuel pump test terminal at DLC. (Scheme 119) Disconnect fuel pump connector (at fuel pump). Turn ignition on. Measure voltage of Black/Pink wire at fuel pump connector. If voltage is less than 10 volts, go to next step. If voltage is greater than 10 volts, Go to step 11).
4. Turn ignition off. Remove fuel pump relay. Ensure fuel pump is disconnected. Disconnect PCM. Check Light Green wire and Black/Pink wire at fuel pump relay connector for continuity to ground. If resistance is 10,000 ohms or more, go to next step. If resistance is less than 10,000 ohms, repair short to ground in Light Green wire or Black/Pink wire.
5. Turn ignition off. Ensure fuel pump relay is disconnected. Turn ignition on. Measure voltage at specified terminal of fuel pump relay connector. See «FUEL PUMP RELAY VOLTAGE»(ref-23202-S09973976492002011100000) table. If voltage is as specified, go to next step. If voltage is not as specified, repair White/Red and/or Purple wires as necessary. FUEL PUMP RELAY VOLTAGE Terminal Ign. Switch Position Voltage White/Red ON 10-14 Purple START 10-14
6. Turn ignition off. Apply battery voltage between terminals "E" and "F" of fuel pump relay. (Scheme 120) Measure resistance between terminals "A" and "C". Resistance should be less than 5 ohms. With no battery voltage applied to relay, resistance between terminals "A" and "C" should be more than 10,000 ohms. If resistance is not as specified, replace relay. If resistance is as specified, go to next step. (Scheme 120): Identifying Fuel Pump Relay Terminals
7. Apply battery voltage to fuel pump relay terminal "C" and ground terminal "B". Connect a test light to battery ground and check for power at relay terminal "A". If test light glows, go to next step. If test light does not glow, replace relay.
8. Turn ignition off. Measure resistance between ground and Black wire at fuel pump relay connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Black wire.
9. Turn ignition off. Ensure fuel pump relay is disconnected. Access Volume Airflow (VAF) meter door. Measure resistance between ground and Light Green wire at fuel pump relay connector. With VAF door closed, resistance should be more than 10,000 ohms. With VAF door open, resistance should be less than 5 ohms. If resistance is not as specified, go to next step. If resistance is as specified, repair Black/Pink wire between fuel pump relay and fuel pump.
10. Turn ignition off. Disconnect VAF meter connector. Access VAF meter door. Measure resistance between Light Green and Black wires (terminals No. 1 and 2) on VAF meter. With VAF door closed, resistance should be more than 10,000 ohms. With VAF door open, resistance should be less than 5 ohms. If resistance is not as specified, replace VAF meter. If resistance is as specified, repair Black wire or Light Green wire between fuel pump relay and VAF meter.
11. If voltage was 10-14 volts in step 3), turn ignition off. Disconnect fuel pump connector. Measure resistance between ground and Black wire at fuel pump connector. If resistance is less than 5 ohms, replace fuel pump. If resistance is 5 ohms or more, go to next step.
12. Turn ignition off. Remove IFS switch. Shake switch to force switch into tripped position (switch open). Measure resistance between IFS switch terminals that connect to Blue and Black wires. With IFS switch open (tripped), resistance should be more than 10,000 ohms. With IFS switch closed (set), resistance should be less than 5 ohms. If IFS switch does not test as specified, replace switch. If IFS switch is okay, go to next step.
13. Ensure ignition is off. Ensure IFS switch is disconnected. Measure resistance between ground and Black wire at IFS switch connector. If resistance is less than 5 ohms, repair Blue wire between IFS switch and fuel pump. If resistance is 5 ohms or more, repair open Black wire.

Scheme 121

1. Turn ignition off. Using jumper wire, connect Data Link Connector (DLC) fuel pump test terminal to ground terminal. (Scheme 119) Disconnect fuel pump connector. Turn ignition on. Measure voltage between ground and Black/Pink wire at fuel pump connector. If battery voltage is present, go to next step. If battery voltage is not present, go to appropriate NO FUEL PRESSURE.
2. Turn ignition off. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(ref-23202-S17210844102001010300000). Remove fuel filter. Inspect filter for restriction and contamination. Replace fuel filter if necessary, and recheck fuel pressure. If fuel filter is okay, go to next step.
3. With fuel pressure released, install fuel pressure gauge between fuel filter and fuel rail. Ensure pressure gauge main valve is open and drain valve is closed. Start engine and run it for 10 seconds. Stop engine and wait for 10 seconds. Start engine again and run it for 10 seconds. Stop engine, and remove vacuum hose from pressure regulator. Check pressure regulator for fuel leakage through diaphragm. (Scheme 121) If fuel is present, replace pressure regulator. If fuel is not present, go to next step. (Scheme 121): Identifying Fuel Pressure Regulator Components
4. Reconnect vacuum hose. Start engine. Run it for 30 seconds. Stop engine and observe fuel pressure. Wait 5 minutes and observe fuel pressure again. If fuel pressure remained high (above 21 psi), go to next step. If fuel pressure dropped to 21 psi or less, start engine and let run for 30 seconds. Stop engine and wait 5 minutes. If fuel pressure is still less than 21 psi, check fuel injectors for leakage. See «FUEL INJECTOR TEST»(ref-23202-S26448793182001010300000). If okay, replace pressure regulator and repeat test.
5. Disconnect fuel return hose at fuel pressure regulator. Connect vacuum gauge to fuel return tube of fuel pressure regulator. Apply 20 in. Hg of vacuum for 10 seconds. If vacuum does not drop to less than 10 in. Hg, go to next step. If vacuum drops to less than 10 in. Hg, replace pressure regulator.
6. Place fuel pressure gauge drain hose into an measuring vessel. Using jumper wire, connect fuel pump terminal to ground terminal at DLC. (Scheme 119) Turn ignition on for 10 seconds. Measure fuel volume. If fuel volume is 5.5 ounces or more, go to next step. If fuel volume is less than 5.5 ounces, service fuel pump inlet screen and repeat fuel volume test. If fuel volume is still less than specified, replace fuel pump.
7. Using a jumper wire, connect fuel pump terminal to ground terminal at DLC. Turn ignition on. Operate fuel pump for 30 seconds. Observe fuel pressure gauge for 3 minutes. If fuel pressure does not decrease more than 2 psi, replace fuel pump. If fuel pressure decreases more than 2 psi, check for leaking fuel injector. See «FUEL INJECTOR TEST»(ref-23202-S26448793182001010300000).

High Fuel Pressure

1. Check for engine vacuum leaks. Check for loose or cross threaded fittings, cracks, and blockage which could cause insufficient vacuum supply to fuel pressure regulator. Repair vacuum leaks as necessary. If no vacuum leaks are found, go to next step.
2. Check fuel pressure regulator housing for damage and dents which could cause a higher spring load on regulator. Check fuel pressure regulator diaphragm for fuel leakage. If fuel pressure regulator is okay, go to next step. Replace fuel pressure regulator if defective, and recheck fuel pressure.
3. Disconnect fuel return line from fuel pressure regulator and fuel tank. Place disconnected hose at fuel tank into an empty container. Using low air pressure (5-10 psi), blow air into disconnected return line at pressure regulator. If fuel return line is restricted, clean or repair return line as necessary and repeat fuel pressure test. If fuel return line is free of restrictions, replace fuel pressure regulator and repeat fuel pressure test.

BY-PASS AIR (BPA) AIR VALVE

1. Remove BPA valve from engine. Allow BPA valve to cool to room temperature. Blow through valve, air should pass freely through valve. Replace valve if air does not flow through valve.
2. Using a heat gun or hair dryer, heat valve to 120°F (49°C). Blow through valve, air should not pass through valve. If air passes through valve, replace BPA valve.

IDLE AIR CONTROL (IAC) VALVE

Disconnect IAC valve electrical connector. Using a DVOM, measure resistance between the 2 terminals on IAC valve. Resistance should be 6-14 ohms. Replace valve if resistance is not a specified.

IGNITION SYSTEM

For ignition system testing, see the BASIC TESTING - 1.8L

article.