How to adjust the clearance of Cummins choke?
In this position, the two valve rocker arms of the fifth cylinder can move freely (the valve is closed). The plunger of the third cylinder injector is located at the top of the stroke; If not, pry the diesel engine another 360 degrees: realign the marks and arrows.
Secondly, install ST- 1 170 dial indicator bracket and dial indicator extension rod on the top of the third cylinder choke plunger. Please note that the dial indicator extension rod is fixed in the dial indicator rod and will not abut against the rocker arm. ?
Note: The nozzle adjustment of the third cylinder and the valve adjustment of the fifth cylinder are just for illustration, and any other cylinder can be used as the starting cylinder, as shown in Table11-15.
Third, use ST- 1 193 rocker arm or similar tools to press the rocker arm toward the fuel injector until the plunger reaches the bottom and the oil film in the cup is squeezed out. Then let the plunger rise, press the plunger to the bottom, and zero the pointer of the dial indicator.
Pay attention to whether the extension rod touches the top of the plunger. Table11-15n-855 diesel engine fuel nozzle and valve adjustment position start a or 1 ~ 6Vs35 turn forward to b or 2 ~ 5Vs63 turn forward to c or 3 ~ 4Vs26 turn forward to a or 1 ~ 6Vs42 turn forward to b or 2.
Fourth, press the plunger to the bottom again and loosen the rocker arm. The pointer should point to the travel specified in table11-16, and adjust if it exceeds it. ?
5. If the lock nut is loose, use 54 ~ 6 1N? M (40 ~ 45ft-1BF) torque? Tighten the nut, and then pull the injector plunger several times to check whether the stroke is adjusted correctly. If ST-669 connector is used, use 4 1 ~ 47N? M(30 ~ 35 lb ft) torque tightening.
Extended data:
Cleaning of automobile fuel nozzle;
As one of the key components of EFI engine, the performance of injector will be seriously affected. Nozzle blockage will seriously affect the performance of the car.
The reason for the blockage is that carbon deposits in the engine are deposited on the fuel nozzle or impurities in the fuel block the fuel nozzle channel. After the car runs for a period of time, the fuel system will form certain deposits.
The formation of deposits is directly related to automobile fuel: firstly, because gasoline itself contains colloid and impurities, or dust and impurities brought in during storage and transportation, deposits similar to sludge are formed in automobile fuel tanks and oil intake pipes over time;
Secondly, the unstable components in gasoline react at a certain temperature to form colloid and resin-like viscous bodies. When these viscous substances are burned in the nozzle, intake valve and other parts, the deposits will become hard carbon deposits.
In addition, due to urban traffic congestion, cars are often at low speed and idle speed, which will aggravate the formation and accumulation of these deposits. The deposits in the fuel system are very harmful. Deposits will block the needle valve and valve hole of injector, affect the working performance of precision parts of EFI system, and lead to the decline of dynamic performance;
Deposits will form carbon deposits in the intake valve, which will lead to the untidy closing of the intake valve, unstable idle speed of the engine, increased fuel consumption and deterioration of exhaust emissions; Deposits will form hard carbon deposits on the piston crown and cylinder head, which is easy to cause engine failure due to its large heat capacity and poor thermal conductivity. In addition, it will shorten the service life of the three-way catalyst.
The work of injector plays an important role in the power of each engine. Due to poor fuel, the injector does not work normally, resulting in serious carbon deposition in the cylinder; The accelerated wear of cylinder and piston ring will cause unstable idle speed, rising fuel consumption, weak acceleration, difficult start-up, excessive emission, complete blockage of injector and damage to engine.
Therefore, it is necessary to clean the nozzle regularly. Long-term non-cleaning or frequent cleaning of the nozzle will have a bad influence. As for the cleaning time, it depends on the condition of the car and the quality of fuel added at ordinary times. Generally speaking, it is recommended that most users clean it once every 20,000 ~ 30,000 km. The car is in good condition and the fuel quality can be extended to about 40,000 ~ 60,000 kilometers.
When the injector is slightly blocked, it also has a certain impact on the vehicle condition. Sometimes, there will be such a fault: the car is a little shaky when it starts in first gear, and it disappears when it accelerates in high gear. Assuming that all kinds of sensors on the car are working normally, the throttle is clean and the circuit is normal, it is likely that the fuel injector is slightly blocked.
However, when accelerating in high gear, slight gum may be sprayed away (dissolved) again, and the performance of the car will be restored. This slight blockage of the fuel nozzle can usually be avoided.
Because slight gum can be dissolved. Therefore, in daily driving, you should always run at high speed to reduce the possibility of carbon deposition.
If the fuel injector is not cleaned for a long time, the blockage will be more serious when the gasoline quality is poor or the vehicle runs for a long time, resulting in poor fuel injection, poor fuel injection angle and atomization, poor engine performance at idle speed, acceleration or full load, reduced engine power, increased fuel consumption, aggravated emission pollution, and even made the engine unable to work.
Therefore, the nozzle should be carefully cleaned and inspected regularly to ensure its good work.
References:
Baidu encyclopedia-automobile fuel nozzle