During the operation of the car, you need to pay attention to deviations from the norm that appear in the engine operation: knocking, interruptions, loss of power, difficulty starting

The specified malfunctions most often arise as a result of violation of the rules of maintenance of power system devices and operating rules.

Before looking for reasons for difficulty starting the engine, check whether there is fuel in the tank and whether the valve of the fuel suction line is open

KAMAZ power supply malfunctions and solutions

Cause - solution

The engine does not start

  • - The fuel lines or the intake in the fuel tank are clogged - wash the intake, rinse and blow out the fuel lines;
  • - Water freezing in the fuel lines or on the fuel tank intake screen - carefully warm up the fuel pipes, filters and tank;
  • - Thickening of fuel in the pipelines - replace the fuel with another one appropriate for the season and bleed the system
  • - Clogged fuel filter elements - replace filter elements;
  • - Incorrect fuel injection advance angle - adjust the injection advance angle;
  • - Presence of air in the fuel system - bleed the system, eliminate leaks;
  • - The fuel priming pump does not work - disassemble the pump and eliminate the malfunction, if necessary, replace the pump with a working one;
  • - Sticking of the high pressure fuel pump rack - repair the pump in a workshop or replace it with a working one;
  • - Difficulty moving the fuel pump rack due to thickening of the lubricant - carefully warm up the high pressure fuel pump

The engine does not develop power and smokes

  • - The air filter is dirty - wash the filter elements;
  • - Clogged exhaust tract - clean the exhaust tract;
  • - The governor control lever does not reach the maximum speed bolt - check and adjust the system of levers and rods;
  • - Presence of air in the fuel system - bleed the fuel supply system and eliminate leaks;
  • - Incorrect fuel injection advance angle - adjust the injection advance angle;
  • - Loose fit of the gas distribution valves - adjust the thermal clearances of the valve mechanism, grind the valves if necessary;
  • - Failure to adjust or clog the nozzle - adjust the nozzle and, if necessary, rinse and clean it
  • - Malfunction of the fuel pump valves - wash the pump sockets and valves;
  • - Violation of the regulation of the cyclic flow of the high-pressure fuel pump - adjust the cyclic flow of fuel;
  • - Damage to the pusher springs of the high-pressure fuel pump - replace the springs and adjust the pump on the stand;
  • - Spring breakage or leakage of the injection valves of the high-pressure fuel pump - tighten the ring gear screw and adjust the pump on the stand;
  • - The plunger of the high pressure fuel pump is stuck - replace the plunger pair and adjust the pump on the stand;
  • - Wear of piston rings - replace piston rings, and, if necessary, cylinder liners

The engine is knocking

  • - Early fuel injection into the cylinders - adjust the fuel injection advance angle;
  • - The valve mechanism adjustment is broken - adjust the thermal clearances in the valve mechanism

Work to eliminate the causes of malfunctions in the power system comes down to checking the normal circulation of fuel all the way from the tank to the injectors, detecting and eliminating air leaks in the system, as well as ensuring the normal operation of the fuel equipment by adjusting it or disassembling and replacing individual faulty parts .

To determine the cause of the malfunction, a sequential check of engine systems and components is carried out.

The sequence of checks was established on the basis of long-term studies of the causes of engine failures and malfunctions according to the principles: “from the most probable cause to the least probable”, “from a simple check to a complex one.”

This approach provides a quick search for the cause.

So, if the engine does not start when the electrical starting system is known to be working, you should check the fuel supply to the injection pump. This can be determined by pumping the system with a manual fuel pump.

The cause of the malfunction may be a lack of fuel in the tank, clogged or leaking low pressure fuel lines.

The slightest leak in the connections in the area from the fuel tank to the fuel pump causes air to be sucked in, which reduces the fuel supply or eliminates it completely.

Leaks can be detected by pumping the low pressure line with a fuel transfer pump (attached to other accessories for the car) due to fuel leakage.

After eliminating leaks, remove air from the power system by pumping it with a manual fuel pump.

If there is no air leak in the low pressure line, then you need to make sure that the low pressure fuel pump is working.

To check the operation of the pump, you need to disconnect the fuel line supplying fuel to the fine filter and turn the engine crankshaft with the starter.

If the pump is working properly, fuel will flow out of the fuel line.

If there is no jet, the pump is faulty unless the fuel lines leading to the fuel tank, the coarse filter element or the fuel intake are clogged.

In case of the most possible malfunctions of the pump (spring breakage or piston hanging, dirt getting between the seat and the valve), it is necessary to disassemble it, eliminate the malfunction and check the operation of the pump on a special stand in the workshop before installing it on the engine.

If the fuel pump is working properly, difficult engine starting may be caused by the fine fuel filter nozzle valve sticking in the open position.

If fuel flows to the injection pump, but the engine does not start, then the cause may be clogged fine fuel filters and should be replaced.

If the filter elements are clean, starting the engine may be difficult due to a violation of the fuel injection advance angle adjustment.

If after checking the engine still does not start, then most likely the injectors or injection pump are faulty.

In a high-pressure fuel pump, most often the rack may become stuck, the bypass valve spring will break or weaken, dirt will get between the seat and the valve, plunger pairs and discharge valves will wear out or hang up, etc.

These faults can only be identified and eliminated in a specialized workshop using bench equipment, so the injectors and injection pump must be removed and sent to the workshop.

In winter, water may freeze in the fuel lines, filters or on the intake screen, and the oil viscosity may increase, which makes it difficult to move the high-pressure fuel pump rack.

In this case, you should try to carefully warm up the fuel lines, filters, fuel tank, and high-pressure fuel pump using a rag and hot water.

You should not use an open flame for heating.

Elimination of the causes of such malfunctions as knocking in the engine and increased engine vibrations, uneven operation - loss of power, is carried out mainly by adjusting the corresponding elements of the fuel equipment or replacing faulty parts.