1. DIAGNOSIS AND TREATMENT OF ENGINE IDLING WITHOUT IDLE SPEEDTHE ENGINE HAS NO IDLE SPEED, WHICH IS GENERALLY MANIFESTED BY THE ENGINE STALLING WHEN THE THROTTLE IS PLACED IN THE IDLE POSITION. WHEN THE THROTTLE IS SLIGHTLY INCREASED, THE SPEED QUICKLY INCREASES AND CANNOT OPERATE STABLY AT LOW SPEEDS.⑴ REASON① THE IDLE SPRING OF THE GOVERNOR IS TOO SOFT OR BROKEN.② THE SENSING ELEMENT OF THE SPEED REGULATOR IS WORN OUT TOO MUCH.③ THE PLUNGER OF THE FUEL INJECTION PUMP IS SEVERELY WORN.④ THE TEMPERATURE IS TOO LOW.⑤ THE CYLINDER PRESSURE IS TOO LOW.⑵ DIAGNOSIS AND TREATMENT METHODS① NO IDLE DURING COLD START IS GENERALLY A NORMAL PHENOMENON. THIS IS BECAUSE THE TEMPERATURE IS TOO LOW AND THE OIL VISCOSITY IS TOO HIGH, WHICH INCREASES THE RESISTANCE IN THE ENGINE AND WORSENS THE SPRAY AND EVAPORATION CONDITIONS OF DIESEL OIL. AS A RESULT, THE ENGINE CANNOT MAINTAIN THE LOWEST STABLE SPEED. WHEN THE THROTTLE IS RAISED, THE ENGINE WILL SHUT DOWN QUICKLY. IN THIS CASE, THE THROTTLE CAN BE ADJUSTED SLIGHTLY ABOVE IDLE TO RESUME IDLE OPERATION AFTER THE ENGINE HAS WARMED UP.② IF THE ENGINE HAS BEEN USED FOR A LONG TIME WITHOUT IDLE CONDITIONS, AND IS ACCOMPANIED BY INSUFFICIENT POWER AND ABNORMAL FUEL CONSUMPTION, IT IS GENERALLY DUE TO EXCESSIVE WEAR OF THE PLUNGER, WHICH INCREASES THE AMOUNT OF OIL LEAKAGE DURING IDLE AND MAKES THE FUEL SUPPLY UNABLE TO MEET THE REQUIREMENTS OF IDLE CONDITIONS; OR THE CYLINDER PRESSURE MAY BE TOO LOW, AND THE FUEL INJECTION ADVANCE ANGLE MAY BE TOO LARGE OR TOO SMALL, RESULTING IN POOR COMBUSTION CONDITIONS IN THE ENGINE. AS LONG AS THE FAULT OF INSUFFICIENT POWER IS HANDLED, THE IDLE CONDITION WILL NATURALLY RECOVER.③ IF THE ABOVE SITUATION IS NORMAL, IT SHOULD BE CONSIDERED WHETHER THERE ARE ANY ABNORMALITIES IN THE IDLE WORKING COMPONENTS OF THE GOVERNOR. CHECK IF THE SPEED REGULATOR SPRING IS BROKEN, OR IF THE SPEED REGULATING COMPONENTS ARE WORN TOO MUCH OR IF THE SPRING IS TOO SOFT, CAUSING THE CENTRIFUGAL FORCE OF THE FLYING HAMMER TO BE MUCH GREATER THAN THE SPRING TENSION DURING IDLE OPERATION AND REDUCING OIL, OR IF THE MAINTENANCE PERSONNEL MAKE IMPROPER ADJUSTMENTS. THE FUEL INJECTION PUMP ASSEMBLY MUST BE REMOVED AND REPAIRED AND ADJUSTED AGAIN ON THE TEST BENCH.WHEN CHECKING THE GOVERNOR, THE FIRST STEP IS TO ADJUST IT WITH THE IDLE SCREW. IF THE ADJUSTMENT IS INEFFECTIVE, THEN ADJUST THE PRE TENSION OF THE IDLE SPRING. YOU CAN SLIGHTLY TIGHTEN THE IDLE SPRING ADJUSTMENT NUT INWARD OR ADD A WASHER ON THE SPRING SEAT TO INCREASE THE PRELOAD AND RAISE THE IDLE SPEED. IF THE SPRING BREAKS, IT SHOULD BE REPLACED AND ADJUSTED TO RESTORE ITS IDLE PERFORMANCE.