1994 MAZDA MX-5 fuel

FUEL SYSTEM 1. Disconnect the negative battery terminal. 2. Remove the PCV hose. 3. Disconnect the vacuum hose. 4. Disconnect the fuel injector connectors. 5. Remove the fuel distributor and the pressure regulator. 6. Remove the grommets, fuel injectors, and insulators. Inspection Fuel leakage test 1. Firmly affix the fuel injectors to the fuel distributor with wire. 2. Disconnect the fuel injector connectors. 3. Remove the fuel distributor and fuel injectors together with the fuel hoses connected. 4. Connect data link connector terminals FIP and GND with a jumper wire. 5. Turn the ignition switch ON. 6. Tilt the fuel injectors approx. 60 degrees and verify that no fuel leaks from the fuel injector nozzles. 7. If fuel leaks from an fuel injector, replace it. Leakage Specification If there is more than one drop per 2 minutes, replace the fuel injector. d 8. Turn the ignition switch OFF and remove the jumper wire. Gartner Banana

FUEL SYSTEM Volume test Warning Fuel vapor is hazardous. It can very easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel. 1. Remove the air valve. 2. Firmly affix the fuel injectors to the fuel distributor with wire. 3. Disconnect the fuel injector connectors. 4. Remove the fuel distributor and fuel injectors together with the fuel hoses connected. 5. Connect the SST to the battery and an fuel injector. 6. Check the injection volume with a graduated container. Injection volumes: 59-76 ml (59-76 cc, 1.8-2.3 fl oz}/15 sec. 7. If not as specified, replace the fuel injectors. lnstallation Install in the reverse order of removal, referring to Instal- lation note. Tightening torque: Delivery pipe 19-25 N.m (1 .%2.6 kgfm, 14--18 ft4bf) FUEL DISTRIBUTOR MANIFOLD C 45UOFX-282 Installation note 1. Use new injector O-rings. 2. Apply a small amount of clean engine oil to the O-rings before installing. 45UOFX-281 INSULATOR O-RING 3. Use new fuel injector insulators. 4. Install the fuel injectors and new fuel injector insulators. Gartner Banana

PRESSURE REGULATOR CONTROL SYSTEM PRESSURE REGULATOR CONTROL SYSTEM DATA LINK CONNECTOR - CLUTCH SWITCH (MT) (TEN TERMINAL) PARKINEUTRAL SWITCH (PCMT) (AT) THROTTLE POSITION SENSOR L 1 ,,,, INTAKE AIR TEMPERATURE 1 SENSOR (IN MASS AIRFLOW SENSOR) -;- ENGINE COOLANT TEMPERATURE SENSOR PRC SOLENOID VALVE CRANKSHAFT POSITION SENSOR PRESSURE REGULATOR PCME I Above 90°C {194OF} ( Above 70°C {158'F} I Throttle valve closed throttle position or no load condition I Approx. 150 1 I Operating condition Coolant temperature I Intake air temperature I Engine condition I I To prevent percolation of the fuel during hot restart idle, vacuum to the pressure regulator is momentarily cut, and the fuel injection pressure is increased to slightly more than 284 kPa (2.9 kgf/cm2, 41.2 psi}. Operating time (sec) Gartner Banana

OUTLINE OF EMISSION CONTROL SYSTEM F OUTLINE OF EMISSION CONTROL SYSTEM STRUCTURAL VIEW .,, The following systems are employed to reduce CO, HC, and NOx emissions. 1. Positive crankcase ventilation (PCV) system. 2. Fuel evaporative system. 3. Three-way catalyst. 4. Deceleration control system. Gartner Banana

FUEL EVAPORATIVE SYSTEM FUEL EVAPORATIVE SYSTEM DESCRIPTION The fuel evaporative system consists of the fuel vapor valve, the two-way check valve, the charcoal can- ister, the purge solenoid valve, the powertrain control module (engine), and the input devices. The amount of evaporative fumes introduced into the engine and burned is controlled by the solenoid valve in relation to the engine's operating conditions. To maintain the best engine performance, the solenoid valve is controlled by the powertrab control module (engine). THROTTLE 1-1 POSITION SENSOR I1 I I (IDLE SWITCH) 7 BAROMETIC ABSOLUTE PRESSURE SENSOR PARWNEUTRAL SWITCH (AT) MASS AIRFLOW SENSOR CRANKSHAFT POSITION SENSOR (SGT-SIGNAL) n - DUTY - LOW HIGH (ENGINE) CHARCOAL PURGE SOLENOID VALVE CANISTER HEATED OXYGEN SENSOR ENGINE COOLANT POWERTRAIN TEMPERATURE SENSOR CONTROL MODULE CHECK VALVE # 11 FUEL VAPOR VALVE Operation The purge solenoid valve is controlled by duty signals from the powertrain control module (engine) to per- form purging of the charcoal canister. Purging is done when these conditions are met: i/ 1. After warm-up. 2. Driving in gear. 3. Accelerator pedal depressed (idle switch OFF). 4. Heated oxygen sensor functioning normally. Gartner Banana

FUEL EVAPORATIVE SYSTEM I GROUND I PURGE SOLENOID VALVE On-vehicle lnspection 1. Warm up the engine to normal operating temperature. 2. Run the engine at idle. d 3. Disconnect the vacuum hose from the purge solenoid valve and verify that no vacuum is felt at the purge sole- noid valve. 4. If not as specified, check the purge solenoid valve. lnspection 1. Disconnect the vacuum hoses from the purge solenoid valve. 2. Verify that no air flows through the purge solenoid valve. 3. Disconnect the purge solenoid valve connector and con- nect battery positive voltage and a ground to the termi- nals of the purge solenoid valve. 4. Verify that the air flows through the valve. 5. If not as specified, replace the purge solenoid valve. TWO-WAY CHECK VALVE lnspection 1. Remove the valve. 2. Check the operation of the valve with a vacuum pump. INSTALLATION DIRECTION Specification I Apply approx. 15 mmHg i0.59 inHg} vacuum at port A 1 Airflow I 1 Agply apgrox. 44 mmH~ (1.73 inHd vacuum at Port 6 1 Airflow 1 3. If not as specified, replace the two-way check valve. THREE-WAY CHECK VALVE lnspection 1. Remove the valve and plug the port C. 2. Check operation of the valve with a vacuum pump. Specification 3. If not as specified, replace the three-way check valve. Apply approx. 37 mmHg {I -46 inHg} vacuum at port A Apply approx. 70 mmHg (2.76 inHg} vacuum at port I3 Airflow Airflow -d Gartner Banana

FUEL EVAPORATIVE SYSTEM FUEL VAPOR VALVE Inspection 1. Remove the valve. 2. Blow through the valve and verify that air flows in the direction shown. 3. Turn the valve over and blow through the valve. Verify that no air flows. 4. Replace the valve if necessary. CHARCOAL CANISTER lnspection Visually check for damage and replace the charcoal can- ister if necessary. Gartner Banana

DECHOKE CONTROL SYSTEM DECHOKE CONTROL SYSTEM DESCRIPTION To clean out excess fuel in cylinders, as in the case of engine flooding, when the engine is cold, no fuel will be injected when the accelerator is held fully depressed while cranking the engine. CRANKSHAFT POSITION SENSOR (NE-SIGNAL) n POWERTRAIN CONTROL MODULE ENGINE COOLANT TEMPERATURE SENSOR I (ENGINE) 1 DETERMINA- TION OF FUEL CUT SPEED Gartner Banana