1994 MAZDA MX-5 Workshop Manual

F INTAKE AIR SYSTEM SYSTEM OPERATION Inspection of Air Leakage Check for possible air leakage and repair or replace as necessary. - 39 4 Gartner Banana

INTAKE AIR SYSTEM THROTTLE VALVE 45UOFX442 THROTTLE BODY Removal 1. Remove the negative battery terminal. 2. Remove the air pipe. 3. Remove the accelerator cable from the throttle lever. Note Before disconnecting the water hoses, drain the en- gine coolant. 4. Disconnect the water hoses. 5. Disconnect the connectors for the idle air control valve and the throttle position sensor. 6. Remove the throttle body. Inspection Do not remove the thin sealing coating from the throttle valve or bore. 1. Verify that the throttle valve is closed throttle position. 2. Verify that the throttle valve moves smoothly when the throttle lever is moved from closed throttle position to wide open throttle. 3. Replace the throttle body if necessary. Installation Install in the reverse order of removal, using a new mounting gasket. Tightening torque: 19-25 N.m (1.G2.6 kgf.m, 14--18 ftlbf) Gartner Banana

INTAKE AIR SYSTEM INTAKE MANIFOLD Removal Warning e Fuel line spills and leaks are dangerous. Fuel can ignite and cause serious injuries or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete the "Fuel Line Safety Procedures" on page F-108. 1. Remove the throttle body. (Refer to above.) 2. Disconnect the vacuum hoses. 3. Remove the accelerator cable. 4. Disconnect the fuel hoses. 5. Disconnect the connectors from the fuel injectors. 6. Remove the fuel distributor and fuel injectors. 7. Remove the injector harness. 8. Remove the intake manifold bracket. 9. Remove the intake manifold. Installation Install in the reverse order of removal, using a new mounting gasket. 4 Tightening torque Intake manifold and fuel distributor: 19-25 N.m (1.9--2.6 kgf-m, 14--18 ft4bf) Injector harness and bracket: 7.9-1 0.7 N-m 180-110 kgf,cm, 70-95.4 in4bf) Gartner Banana

INTAKE AIR SYSTEM ENGINE ROOM COMPARTMENT 'OR ACCELERATOR PEDAL AND CABLE Accelerator Cable Inspection 1. Check deflection of the cable. If deflection exceeds 1-3mm (0.039-0.118 in), adjust it by turning nut A. 2. Depress the accelerator pedal to the floor and verify that the throttle valve opens fully. Adjust with bolt B if neces- sary. Replacement 1. Remove the accelerator cable from the throttle lever. 2. Loosen the throttle adjustment nuts and remove the cable from the bracket. 3. Compress the tabs of stay C and remove the accelerator cable from the pedal arm. 4. Compress the tabs of stay D and push the cable through the firewall. 5. Remove the accelerator cable. 6. Install in the reverse order of removal. 7. Adiust deflection of the cable after installation. (Refer to I 45~0~~-215 adbve.) Accelerator Pedal Replacement 1. Disconnect the accelerator cable. 2. Remove the accelerator pedal as shown in the figure. 3. Install in the reverse order of removal. ACCELERATOR PEDAL Gartner Banana

F IDLE SPEED CONTROL SYSTEM IDLE SPEED CONTROL SYSTEM DESCRIPTION - -- - THROTTLE VALVE IDLE TO INTAKE MANlF INTAKE i AIR CONTROL VALVE ENGINE COOLANT To improve idle smoothness, the ISC system controls the intake air amount by regulating amount of the bypass air that passes through the throttle valve. This system consists of the air valve that functions only 1 when the engine is cold, the idle air control valve that works throughout the entire engine speed range, and the control system. Gartner Banana

IDLE SPEED CONTROL SYSTEM PREPARATION SST I 'L 49 801 9 9AO For inspection of air System valve Selector BAC VALVE System Operation Air valve - Perform this inspection when the engine is cold. (Engine coolant temperature below 20°C {68OF).) 1. Connect a tachometer to the data link connector terminal IG-. When using an externally powered timing light and/ or tachometer connect it to the power connector (Blue: 1 -pin). Caution Grounding the power connector terminal (Blue: 1-pin) will burn out the 20A wiper fuse. 2. Connect the SST and set the TEST SW to "SELF TEST" or connect data link connector terminals TEN and GND with a jumper wire. 3. Verify that the engine speed gradually decreases as the engine warms up. 4. Remove the SST or the jumper wire. Gartner Banana

IDLE SPEED CONTROL SYSTEM Removal 1 Inspection / RUBBER, REPLACE 1. BAC valve System operation . . . . . . . . . . . page F-105 IDLE AIR CONTROL VALVE lnspection 1. Disconnect the idle air control valve connector 2. Connect an ohmmeter between the terminals of the idle air control valve and measure the resistance. Resistance (at 20°C (68°F)): 11.5 2 0.8Q 3. If not as specified, replace the BAC valve. Gartner Banana

FUEL SYSTEM F FUEL SYSTEM DESCRIPTION . This system supplies the necessary fuel for combustion at a constant pressure to the fuel injectors. Fuel is metered and injected into the intake manifold according to the injection control signals from the power- train control module (engine). The system consists of the fuel tank, the fuel pump, the fuel filters, the fuel distributor, the pressure regulator, the fuel injectors, and the fuel pump relay. I I 1. Fuel tank 5. Fuel pump relay Removal / Inspection / Inspection .................. page F-117 Installation ................ page F-111 Replacement ............... page F-117 2. Fuel filter 6. Pressure regulator Replacement ............... page F-113 Inspection .................. page F-118 3. Fuel pump Replacement ............... page F-119 .................. w Inspection page F-114 7. Fuel injector Replacement ............... page F-115 Inspection .................. page F-119 4. Fuel distributor Removal ................... page F-119 Installation ................. page F-121 Gartner Banana