Debugging Method for PT Oil Pump of Cummins Generator Set 2

This article continues to introduce the on-site debugging method of the PT oil pump for Cummins generator sets.

4. Diesel outlet pressure.

Method 1: Use a diesel engine and a dynamometer to load the diesel engine, check the breakpoint of the governor, and when the throttle valve is fully open, increase the load to the rated speed of the diesel engine, paying attention to the pressure at the output end. When the pressure value is below or exceeds the limit, adjust as follows: unscrew the adjusting screw with the maximum opening of the throttle valve, and add an appropriate thickness of gasket on the valve shaft to increase the pressure; Removing the throttle valve liner with appropriate thickness can reduce pressure. Regardless, the pressure of the PT fuel pump must not exceed the maximum pressure.

Method 2: Check that the diesel outlet pressure drops from low to high to maximum when the throttle valve is fully open. If the pressure is lower than the minimum mechanical pressure or the specified maximum value, it should be corrected according to the method.

Method 3: Also known as instantaneous, pressure detection method; This method is more accurate and simple than methods 1 and 2, that is, unscrew the oil cut-off solenoid valve and install the pressure gauge, remove the connecting piece on the throttle valve rocker arm (throttle valve rocker arm), and tighten the connecting rod on the throttle valve rocker arm. This method is explained. After the repair is completed, remove the pressure gauge, install the oil solenoid valve, block the pipeline, and control the smoke.

5. The throttle is leaking.

When the throttle valve is fully opened, the blood fuel pressure injected into the injector should meet the pressure, and the maximum fuel volume should meet the regulations. When fully closed, use a limit screw to open a small amount of fuel in the oil pipe, which is called throttle valve leakage. The throttle valve is too large, causing the engine to slow down and the air leakage is too small. Closing it will cause the diesel engine to slow down.

The throttle valve is generally tested on the PT fuel pump test bench. If it is necessary to correct the leakage of the throttle valve on site, the throttle valve joint must be adjusted to close the position of the throttle valve (at this time, the throttle valve on the PT fuel pump is in contact with the fastening screw of the throttle valve), or the throttle valve must be fully opened to put the diesel motor in the maximum no-load state, and checked with a stopwatch or other appropriate timer and tachometer. The steps are as follows:

(1) Quickly open the throttle or adjust it to the off position, press the stopwatch.

(2) When the diesel engine reaches 1000RPM, stop the stopwatch, pay attention to the deceleration time, and take the average value multiple times.

(3) When a diesel engine releases the accelerator pedal at its rated no-load speed and malfunctions (diesel engine idle control), the leakage of the throttle valve will definitely increase. However, the leakage when the throttle valve is opened will enter the adjustment screw (front throttle valve fixing screw) for adjustment. Is the appropriate inspection method modified to deceleration time (average value according to steps 1 and 2), add 1-2 seconds, lock the correction screw at that position, immediately check the idle speed, and make necessary corrections.

(4) When the deceleration time of the Cummins diesel engine is too long (relative to the average speed), the throttle valve oil leakage should be reduced, and the screw should be adjusted to avoid oil leakage from the regulating valve body. Before calibration, it is necessary to use a stopwatch to check the stopping and deceleration time of the engine at high idle speed. If the measurement time is greater than the average of steps A and B, then there is no throttle leakage. If the deceleration time is greatly reduced, it indicates air leakage. If the deceleration value is shortened, the oil leakage of the throttle valve will decrease. Therefore, the throttle speed adjustment screw can be tightened. As mentioned above, check if the deceleration rate of the diesel engine has decreased. If the diesel engine slows down from no-load speed and stalls due to overheating, the screw should be tightened, the deceleration time should be increased by 1-2 seconds, and the adjustment screw in that position should be locked; Then, if necessary, correct the idle speed.

Dingbo Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.