Tune-Up - Rotary Mazda RX-7 FC

ENGINE IDENTIFICATION

The engine code is stamped on rear rotor housing, to the rear of the oil filter. The engine serial number is stamped on the front rotor housing behind the crank angle sensor.

ENGINE CODE

ENGINE COMPRESSION

1. Manufacturer recommends using a special Compression Tester (49 F018 9A0). Compression testers for piston engines will read only the highest pressure of the 3 combustion chambers in the rotor housing.
2. Check that battery is fully charged. Warm engine to operating temperature. Turn it off for about 10 minutes to reduce exhaust pipe temperature. Remove front and rear trailing-side spark plugs.
3. Disconnect crank angle sensor connector. Connect compression tester with adapter to front rotor housing and battery. Fully depress accelerator pedal and crank engine for 5-10 seconds. Make a note of compression of the 3 combustion chambers and cranking speed. Check rear chambers with same procedure.

COMPRESSION SPECIFICATIONS

HIGH TENSION WIRE RESISTANCE

HIGH TENSION WIRE RESISTANCE

High Tension Wire Routing

For high tension wire routing (Scheme 1)

Scheme 1

FUEL PUMP

FUEL PUMP PERFORMANCE

IGNITION TIMING

1. Warm engine to normal operating temperature. Turn off all electrical loads. Connect tachometer and check idle speed. Connect timing light to high-tension lead of front leading side.
2. Check that mark on pulley is aligned with indicator pin. Connect timing light to high-tension lead of front trailing side, and check timing. If necessary, turn crank angle sensor to adjust. The Yellow mark is 5 degrees ATDC and the Red mark is 20 degrees ATDC.

IGNITION TIMING (DEGREES ATDC @ RPM)

Scheme 2

1. Switch off all accessories, connect a tachometer to engine, warm engine to normal operating temperature, and connect a jumper wire to terminals of initial set coupler. (Scheme 2)
2. Connect tachometer to service coupler (Black wire, Black connector) at trailing side coil. If tachometer does not function correctly on trailing side coil, reconnect at leading side coil Black wire terminal).
3. If using an inductive (secondary pick-up) type tachometer, connect it only at trailing side high tension leads. If connected on the leading side coil, it will function incorrectly.
4. Check and adjust throttle sensor. Remove blind cap and adjust idle speed by turning air adjust screw. (Scheme 3) Adjust to 725-775 RPM with transmission in "Neutral". Install blind cap and disconnect jumper wire from initial set coupler.

Note. If jumper wire is not removed, engine performance is reduced. Make certain that jumper wire is removed.

Scheme 3

IDLE MIXTURE

Note. Usually idle mixture adjustment is unnecessary. Idle mixture adjustment should be performed only when the variable resistor or the engine is replaced.

Variable Resistor Inspection

Disconnect variable resistor connector. Check resistance or variable resistor using a circuit tester. Resistance should be 500-4500 ohms between terminals "A" and "C", and between terminals "B" and "C". (Scheme 4) Replace resistor if necessary. Adjust idle mixture.

Scheme 4

Scheme 5

1. Switch off all accessories, connect a tachometer to engine, warm up engine to normal operating temperature, and connect a jumper wire to terminals of initial set coupler. (Scheme 2)
2. Connect a tachometer to service coupler (Black coupler) at trailing side coil. If tachometer does not function correctly on trailing side coil, reconnect at leading side coil negative side Black wire terminal). If using an inductive (secondary pick-up) type tachometer, connect it only at trailing side high tension leads.
3. Check and adjust throttle position sensor. (Scheme 7) Remove blind cap and adjust idle speed to 750 RPM by turning air adjust screw. (Scheme 3) Next, set idle speed to highest RPM by turning variable resistor. (Scheme 5) Then, reset idle speed to 750 RPM by turning air adjust screw.
4. Turn variable resistor counterclockwise until idle speed is lowered to 730 RPM, and then turn it clockwise to reset speed to 750 RPM. Install blind cap and disconnect jumper wire. Plug head of adjust screw with Adhesive Agent (N304 23 795).

Note. If jumper wire is not removed, engine performance will be reduced. Make certain that jumper wire is removed.

Adjustment

1. Warm up engine, then stop it. Connect Checker Light 49 F018 001) to check connector (Green). (Scheme 6) Turn ignition switch on and check whether one of the lights illuminates. If both lights illuminate or if neither does, turn the throttle position sensor adjusting screw until only one of the lights illuminates. (Scheme 7)
2. If both lights illuminate, turn adjusting screw counterclockwise. If both lights do not illuminate, turn adjusting screw clockwise. Reinstall cap on adjusting screw after adjusting.

Scheme 6

Scheme 7

Inspection

Disconnect throttle position sensor connector. Connect an ohmmeter to sensor. (Scheme 8) Open throttle valve and observe sensor resistance. With throttle opening at idle position, there should be 1000 ohms and at wide open throttle there should be 4000-6000 ohms.

Scheme 8

BELT ADJUSTMENT

BELT ADJUSTMENT

DISTRIBUTOR

The RX7 engine is equipped with computer controlled ignition. The system has no distributor. It uses 2 coils controlled by the computer to fire the spark plugs. The computer receives input from a crank angle sensor and then outputs a signal to the leading or trailing coil to fire.

IGNITION COIL

IGNITION COIL RESISTANCE - OHMS @ 68°F (20°C)

SPARK PLUGS

SPARK PLUG TYPE

SPARK PLUG SPECIFICATIONS

Scheme 9

FUEL INJECTION

All RX7 models are equipped with a Electronic Gasoline Injection (EGI) fuel injection system.

BATTERY

BATTERY SPECIFICATION

SERVICE INTERVALS

REPLACEMENT INTERVALS

CAPACITIES

FLUID CAPACITIES