VISUAL INSPECTION
Visually inspect all electrical wiring, looking for chafed, stretched, cut or pinched wiring. Ensure electrical connectors fit tightly and are not corroded. Ensure vacuum hoses are properly routed and are not pinched or cut. See VACUUM DIAGRAMS article to verify routing and connections (if necessary). Inspect air induction system for possible vacuum leaks.
SPARK TEST
- Disconnect high tension coil wire from distributor. Hold coil wire approximately 1/2" away from cylinder block. CAUTION: To prevent gasoline from being injected, DO NOT crank engine for longer than 2 seconds.
- Crank engine and check for spark. If spark does not occur, check ignition coil, ignitor and distributor electrical connections.
- If electrical connections are okay, using ohmmeter, check resistance of high tension wires. Replace high tension wires if resistance is not within specification. See «HIGH TENSION WIRE RESISTANCE»(ref-21327-S40305849452001010300000) table. If resistance is within specification, proceed to step 4). HIGH TENSION WIRE RESISTANCE Application Maximum Ohms Supra 25,000 Per Wire
- Check voltage at ignition coil and ignitor. Turn ignition on. Ensure voltage exists at ignition coil positive terminal. If voltage exists, proceed to step 6). If voltage does not exist, check wiring between ignition switch, ignition coil and ignitor. See «WIRING DIAGRAMS»(ref-21402) article for wiring circuit.
- Check ignition coil resistance. See «IGNITION COIL RESISTANCE»(ref-21327-S13995455602001010300000) under IGNITION CHECKS. Replace ignition coil if resistance is not within specification. If ignition coil resistance is within specification, proceed to step 6).
- Check pick-up coil resistance. See «PICK-UP COIL RESISTANCE»(ref-21327-S33401262862001010300000) under IGNITION CHECKS. Replace pick-up coil or distributor assembly if pick-up coil resistance is not within specification. If pick-up coil resistance is within specification, proceed to step 7).
- Check pick-up coil air gap. See «PICK-UP COIL AIR GAP»(ref-21327-S29889755942001010300000) under IGNITION CHECKS. If pick-up coil air gap is incorrect, replace distributor assembly. If pick-up coil air gap is correct, proceed to step 8).
- Check ignition IGT signal from ECM. If ignition IGT signal from ECM is defective a diagnostic trouble code will be set in the ECM memory to indicate a ignitor circuit malfunction. See information in articles listed below for diagnostic trouble code. If IGT signal is okay, replace ignitor.
TESTS W/CODES - NON-TURBO
TESTS W/CODES - TURBO
- Disconnect negative battery cable. Remove oil filler cap. Remove timing belt cover and gasket, located above ignition coils. (Scheme 2) Remove PCV hoses. Disconnect engine wiring clamps on ignition coils.
- Disconnect electrical connectors from ignition coils. Remove bolts and ignition coil assemblies. Reconnect negative battery cable and electrical connectors on ignition coils.
- Remove spark plugs. Install spark plug on each ignition coil. Ground spark plug against cylinder block. CAUTION: To prevent gasoline from being injected, DO NOT crank engine for longer than 2 seconds.
- Crank engine and check for spark. If spark does not occur, check ignition coil and ignitor electrical connections.
- If electrical connections are okay, turn ignition on. Ensure voltage exists at ignition coil positive terminal. If voltage exists, proceed to step 6). If voltage does not exist, check wiring between ignition switch, ignition coil and ignitor. See «WIRING DIAGRAMS»(ref-21402) article for wiring circuit.
- Check ignition coil resistance. See «IGNITION COIL RESISTANCE»(ref-21327-S13995455602001010300000) under IGNITION CHECKS. Replace ignition coil if resistance is not within specification. If ignition coil resistance is within specification, proceed to step 7).
- Check resistance of camshaft position sensor(s) and crankshaft position sensor. See «CAMSHAFT POSITION SENSOR»(ref-21327-S41958757252001010300000) and «CRANKSHAFT POSITION SENSOR»(ref-21327-S07710627412001010300000) under IGNITION CHECKS.
- Replace camshaft position sensor or crankshaft position sensor if resistance is not within specification. If camshaft position sensor and crankshaft position sensor resistance values are within specification, proceed to step 9).
- Check ignition IGT signal from ECM. If ignition IGT signal from ECM is defective a diagnostic trouble code will be set in the ECM memory to indicate a ignitor circuit malfunction. See information in articles listed below for diagnostic trouble code.
TESTS W/CODES - NON-TURBO
TESTS W/CODES - TURBO
If IGT signal is okay, replace ignitor. Reinstall ignition coils, spark plugs and remaining components.
