The Common Troubleshooting Methods of Cummins Generator PT Fuel System

At present, Cummins generators are widely used in various fields due to their light weight, small size, large power, high torque, good fuel economy, low emissions, low noise, etc., especially the PT fuel system that uses Cummins patented technology. So that the fuel supply status of the generator can better adapt to changes in external load.

Features of Cummins Generator PT Fuel System

1. The injection pressure range is as high as 10,000-20,000 PSI (PSI is pounds per square inch, about 6.897476 kPa), which can ensure good fuel atomization. The fuel pressure output by the PT fuel pump should not exceed 300PSI at most.

2. All fuel injectors share a fuel supply pipe, even if some air enters the fuel system, the engine will not stall.

3. The PT oil pump does not require timing adjustment, and the oil volume is controlled by the oil pump and the nozzle, and the engine power can be kept stable without power loss.

4. About 80% of the fuel is used to cool the fuel injector and then returned to the fuel tank, and the fuel injector is well cooled.

5. Good versatility. The same basic pump and injector can be adjusted for the power and speed changes of different types of engines in a wide range.

For some common faults of the PT fuel system, the user can first perform a simple treatment to solve the problem according to the following methods.

1. When the engine is difficult to start (cannot be started), the power is not enough or cannot be stopped, and the engine is not stalled, it is judged as the  parking valve failure: First, the manual shaft is used to open and close the parking valve, and the manual shaft is screwed in until it cannot be screwed, it is open. Unscrew the manual shaft when parking, but also screw it until it can't be screwed, it is off. Secondly, disassemble the parking valve, clean the parts of the parking valve, and grind the hole in the valve body with sandpaper.

2. When the generator set is traveling (rotating speed is unstable). First disassemble the EFC electronic actuator. When disassembling, first loosen the mounting screws, then rotate the EFC actuator 15°, then remove the actuator, clean it, and then reinstall the fuel pump body as follows: insert the actuator into the fuel pump body, Until the actuator flange is about 9.5mm away from the fuel pump body, then gently push the actuator into the fuel pump EFC mounting hole with the palm of your hand, and turn it 30. , Until the actuator flange touches the fuel pump body. Tighten the mounting screw in a clockwise direction from the bottom end, first tighten it by hand until it stops, and then tighten it with a wrench. In addition, it is necessary to check whether the shock absorber diaphragm is recessed or whether there are hidden cracks. First remove the shock absorber, then disassemble the shock absorber, check whether the shock absorber diaphragm is sunken or drop the shock absorber diaphragm onto a hard surface, there should be a crisp sound, if the sound is dull, you need to replace the shock absorber diaphragm.

3. When the engine with AFC has too much smoke or insufficient power when accelerating, the airless adjustment screw can be adjusted (only when the single-spring AFC has no air adjustment screw on the fuel pump body). If the smoke is large, go to the pump body Screw inside. If the power is not enough, screw it out. Note: Only screw in and out within half a turn.

4. If it is confirmed that the drive shaft of the gear pump is broken, replace the gear pump assembly. First remove the faulty gear pump assembly, and then replace the gear pump assembly removed from the epicyclic pump.

5. For full-range pumps and generator pumps, if the engine power is insufficient, the throttle shaft throttle can be appropriately increased, that is, the front limit screw can be retracted. If it is a vehicle pump or a fuel pump whose throttle shaft is not locked at full throttle, this throttle cannot be changed.

6. The idling speed of the fuel pump can be adjusted: because the idling speed adjusted by the fuel pump on the test bench is a value, but the adapted host is very different, so the idling speed of the fuel pump can be adjusted. The idle speed of the two-pole governor is adjusted in the two-pole spring group cover, and the idle speed of the VS governor is adjusted by the idle speed adjustment screw. 

7. Replace the filter element in the front filter of the parking valve: Note that when the filter element is installed, the small hole faces inward and the spring big end is outward.

8. Replace the O-ring and spring of the injector: When replacing, ensure that no dirt enters the inner cavity of the injector. After replacing the spring, reinstall the injector plunger. Make sure that the injector plunger is clean and free of dirt, and that it is screwed in without obstruction.

The above is the common troubleshooting methods of Cummins generator PT fuel system compiled by the diesel generator manufacturer, Guangxi Dingbo Power Equipment Manufacturing Co., Ltd. We hope it will be helpful to you. Of course, when the actual failure problem occurred, there may be some situations that are different from the above. The user should make specific analysis under different cases, if necessary, for technical support, please email us at dingbo@dieselgeneratortech.com.