Possible malfunctions of the ZMZ-402 and ZMZ-4021 engines of the GAZ-3110 car
If you think that the engine sounds that were not there before, immediately check if everything is in order with the engine
Most often, engine knocks are associated with serious malfunctions, for diagnosing and eliminating which you will have to disassemble the engine in a service or garage.
You can try to determine the cause of the knocks yourself in order to decide whether to go to the car service on your own or in tow.
Cause of malfunction (Remedy)
Engine won't start
Lean mixture (pops in carburetor):
- the mesh filter of the carburetor, fuel pump or fine fuel filter is clogged
Wash the filter in unleaded petrol and blow it out with compressed air
- the diaphragm is torn or the tightness of the fuel pump valves is broken
Replace diaphragm or valves
- water in the sump or fuel line has frozen
Heat the sump or fuel line with hot water
- clogged fuel line
Blow out the fuel lines
- the carburetor air damper does not close completely;
Adjust air damper actuator
- clogged jet: main fuel and idle;
Wash in unleaded gasoline and blow jets with compressed air
- the fastening of the carburetor to the intake pipe or the intake pipe to the cylinder head has loosened;
Tighten fasteners, replace gaskets if necessary
- low fuel level in the carburetor float chamber
Adjust fuel level
- the EGR valve sticks in the open position
Replace recirculation valve
Rich combustible mixture (pops in the muffler when starting the engine):
- the carburetor air damper does not open completely;
Adjust air damper actuator
- the tightness of the fuel supply valve is broken;
Replace the valve seal
- the tightness of the float is broken;
Repair the float or replace the float
- clogged air jets of dosing systems;
Rinse jets with unleaded petrol and blow with compressed air
- adjustment of the mixture quality screw is broken;
Adjust the desired composition of the mixture
- too high fuel level in the carburetor float chamber
Adjust fuel level
The engine does not start in cold weather:
- The air damper does not close
Adjust air damper actuator
Engine runs erratically at idle
- High or low fuel level in the carburetor float chamber
Adjust fuel level
- Wrong idle speed
Adjust the desired composition of the mixture
- A large amount of water in the sump of the fine fuel filter and the fuel tank
Drain sediment from filter and tank
- Incorrect adjustment of clearances in the valve drive
Adjust valve clearances
- The fastening of the carburetor, intake pipe, gas pipeline has loosened
Tighten fasteners, replace gaskets if necessary
Increased toxicity of exhaust gases
- Rich combustible mixture
See "Engine will not start (Rich mixture)"
- Adjustment of gaps in the valve drive is broken
Adjust valve clearances
The engine does not develop full power and does not have sufficient throttle response:
- Faulty carburetor accelerator pump
Check pump flow, replace damaged parts
- Low fuel level in the carburetor float chamber
Adjust fuel level
- Adjustment of gaps in the valve drive is broken
Adjust valve clearances
- Carburetor throttles do not open fully
Adjust the throttle actuator
- Poor combustible mixture
See "Engine will not start (lean mixture)"
- Clogged air filter element
Replace filter element
- Adjustment of gaps in the valve drive is broken
Adjust valve clearances
- The position of the dampers "Winter-Summer" does not correspond to the season
Set dampers for the season
Increased fuel consumption
- Poor or rich combustible mixture
See "Engine won't start"
- Clogged air filter element
Replace filter element
- Wrong initial ignition timing
Adjust ignition timing
- The vacuum corrector of the ignition distributor is faulty
For change the vacuum corrector or distributor
- The tightness of the power supply system is broken
Restore tightness
- Increased resistance to vehicle movement
Check and adjust the brake system, wheel bearings, tire pressure
Engine overheating
- Faulty thermostat
Replace thermostat
- Weak tension of the fan and water pump drive belts
Adjust belt tension
- Wrong initial ignition timing
Adjust ignition timing
- Poor combustible mixture
See "Engine will not start (lean mixture)"
- Severe contamination of the radiator
Rinse the cooling system, flush the radiator with a jet of water
- Increased resistance to vehicle movement
Check and adjust the brake system, wheel bearings, tire pressure
- Faulty water pump
Replace pump
- The engine continues to run after the ignition is turned off
Motor overheat See "Motor overheat"
- Low octane fuel used
Use fuel with the correct octane rating
Knock knocks in the engine
- Early ignition timing
Adjust ignition timing
- A large layer of soot on the walls of the combustion chambers and piston bottoms
Clean carbon deposits
- Low octane fuel used
Use fuel with the correct octane rating
Insufficient oil pressure on a warm engine
- Faulty or clogged oil pressure reducing valve
Rinse the valve parts and the seat in the oil pump housing, if necessary, replace the spring or valve
- Faulty oil pressure sensor or gauge
Check the pressure with a control pressure gauge, replace the defective device
- Engine overheating
Turn on the oil cooler, eliminate the cause of overheating
- Large wear of the main bearing shells
Replace Earbuds
- Wear of oil pump parts
Replace the gasket between body and cover with a thin paper gasket or replace the pump
Increased oil consumption
- Large wear of piston rings
Replace piston rings
- Clogged crankcase ventilation system
Rinse with unleaded gasoline and blow out with compressed air the hoses and ventilation channels in the intake pipe and the parts of the oil separator in the rocker cover
- Oil leakage through engine seals
Tighten connections, if necessary, replace gaskets or seals
- Large wear or destruction of valve stem seals
Replace caps
Engine knocks
- Wear of the connecting rod and piston group
Repair the engine
- Large gaps between rocker arms and valves
Adjust valve clearances
- Large gaps between valve stems and guide bushings
Replace worn parts or valve head assembly
- Wear of camshaft cams and pushers
Replace worn parts
- Large gap between thrust rings and crankshaft
Replace thrust rings