Cause of malfunction - Remedy

The engine does not start

The carburetor, fuel pump or fuel purification filters are clogged - Wash the filters, article - How to replace the fuel filter of a Gazelle car

The pump diaphragm is damaged or the valves are not sealing - Replace the diaphragm. Replace the pump valve, article - Repair of the GAZ-2705 power system with the ZMZ-402 engine

Water has frozen in the coarse and fine fuel filters or in the fuel lines - Warm it up and blow it with compressed air.

The float chamber fuel supply valve is stuck in the closed position - Wash the valve with gasoline, replace the sealing washer

Poor fuel mixture (pops into the carburetor)

The air damper does not close completely - Adjust the air damper

Carburetor jets are clogged - Wash and blow out the jets

Punctured intake manifold or carburetor gaskets - Replace gaskets

Low gasoline level in the carburetor float chamber - Adjust the level

Exhaust gas recirculation valve stuck open - Replace EGR valve

Rich fuel mixture (pops into muffler)

The carburetor air damper is closed - Adjust the air damper

Fuel supply valve seal is broken - Replace valve seal

The carburetor air jets are clogged - Blow the jets with compressed air

The fuel quality screw is too loose - Adjust the fuel supply

Increased level in the float chamber - Adjust the position of the carburetor float

The engine does not start in cold weather

The air damper does not close - Check visually by removing the air filter cover and adjust the air damper.

The ignition coil is faulty - Check the coil, replace if faulty

The switch is faulty - Replace the switch

No contact in the ignition circuit - Tighten the contacts.

Distributor faulty - Replace distributor

Unstable engine operation

The fuel level in the float chamber does not correspond to the specifications - Adjust the level.

Idle speed not adjusted - Adjust idle speed using carburetor adjusting screws.

Valve clearances do not meet specifications - Adjust valves

The slider, distributor cap, or ignition coil is faulty - Replace the slider, check and replace the coil, replace the distributor cap, article - Ignition system ZMZ-402 engine

Failure of intake pipe gaskets or carburetor gaskets - Replace gaskets

The spark plugs or one spark plug are faulty - Check the faulty spark plugs and replace them

The vacuum regulator tube is not sealed or, on the contrary, clogged or kinked - Check the vacuum regulator tube, replace if a malfunction is detected

One or more cylinders operate intermittently

Failure of a high voltage wire - A bad high voltage wire can be seen by sparking in the dark.

Replace the high voltage wire or set of wires.

Distributor cover malfunction - Replace distributor cover

Faulty spark plugs - Replace the faulty spark plug, or a set of spark plugs, article - GAZ-2705 spark plugs

Coil faulty - Check the high voltage coil. Replace the coil.

Increased gas toxicity (engine smokes)

The ignition timing does not correspond to the specifications - Adjust the timing

Wear of oil seals - Replace valve seals

Increased wear of the cylinder-piston group - Repair the engine.