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INSPECTION PROCEDURE USING AN OSCILLOSCOPE TSB Revision MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS 13Ab-53 Wave Pattern Observation Points 1. Check that cycle time T becomes shorter when the engine speed increased. . Examples of Abnormal Wave Patterns • Sensor interface malfunction. Wave pattern characteristics • Rectangular wave pattern is output even when the engine is not started. Example 2 • Loose timing belt. • Abnormality in sensor disc. Wave pattern characteristics • Wave pattern is displaced to the left or right. AKX01600 2 ENGINE REVOLUTIONS (1 CAMSHAFT REVOLUTION) 75 BTDC 5 BTDC T CYCLE TIME CHANGES CRANKSHAFT POSITION SENSOR OUTPUT WAVE PATTERN CAMSHAFT POSITION SENSOR OUTPUT WAVE PATTERN TDC: TOP DEAD CENTER NO.1 TDC NO.2 TDC NO.3 TDC NO.4 TDC NO.5 TDC NO.6 TDC TIME Standard wave pattern AB AKX01597 AKX01602 |