Low idle:

  • - Idling adjustment of the engine is broken (See Adjusting the carburetor K-151 of a GAZ-3110 car) Adjust the idle speed
  • - Incorrect ignition timing (See "GAZ-3110 Ignition Installation") Adjust the ignition timing
  • - engine not warm (By temperature gauge) Warm engine up to operating temperature
  • - Air inlet into the intake manifold (Inspect the joints, check the fit of the hoses, fittings, tightness of the clamps)

Temporarily disable the vacuum brake booster by pinching the appropriate hose (the effort on the brake pedal will increase significantly!)

Torn gaskets, parts with deformed flanges, defective vacuum booster, replace

- Clogged carburetor fuel jets (main fuel and idle). The engine starts only after a few vigorous presses on the gas pedal.

A hot engine starts better than a cold one. Inspect, blow channels and jets.

Rinse with gasoline or acetone and blow through the jets, if heavily soiled, clean them with a fishing line or a soft wood needle (toothpick). Tighten the jets tightly (do not damage the threads and the jet!)

- Insufficient fuel level in carburetor float chamber / The engine does not start well and does not pull well. Pops in the carburetor are possible.

When you pull the "suction" button, markets and dips decrease or disappear completely. Lift the carburetor cover to check the fuel level. Adjust fuel level

- The fuel pump does not create the necessary pressure in the system, the engine starts poorly and pulls poorly.

Check the pressure at the outlet of the fuel pump (at least 3.5 kgf/cm2) and make sure the gas filter is clean.

Clean the fuel gauge. Fuel pump that does not provide the desired pressure in the system - replace

- The fuel pressure regulator is faulty (the drain channel is constantly ajar) ( The engine starts for a long time)

Using a suitable tee, connect a pressure gauge to the inlet hose of the fuel rail - the fuel pressure in the rail must be at least 2.5 kgf / cm2 at idle.

If this is not the case, pinch the outlet hose, the pressure should increase (this indicates that the fuel pump and supply line are working). Replace defective regulator

- Excessive fuel level in carburetor float chamber. There is a strong smell of gasoline from the exhaust pipe, a cold engine starts better than a hot one.

Remove the top cover of the carburetor, check the tightness of the float, its ease of movement and the absence of touching the walls of the float chamber.

Checking the tightness of the needle valve: after removing the carburetor cover and pulling the float up with your finger, pump gasoline with the fuel pump lever.

The slightest leak of gasoline from under the needle or valve seat is unacceptable. Replace leaking needle valve, adjust fuel level in float chamber

- Carburetor fuel jets are loose. Air jets clogged. There is a strong smell of gasoline from the exhaust pipe, a cold engine starts better than a hot one.

Fuel level in float chamber is normal (lift carb cap to check)

Rinse with gasoline or acetone and blow through the jets, if heavily soiled, clean them with a fishing line or softwood needle. Tighten the jets tightly (do not damage the threads and the jet!)

- The idle speed controller or its electrical circuit is faulty.

Substitute a known-good regulator. Replace faulty regulator

- Increased airflow resistance in the intake tract.

Check the air filter element, the intake tract (no foreign objects, leaves, etc.) Clean the intake tract, replace the dirty air filter element

High idle:

  • - Engine idle control out of order / See Carburetor adjustment K-151 car GAZ-3110. Adjust idle speed
  • - long ride while in high engine speeds. After 30-40 seconds of idling, the speed drops to normal. Not a malfunction
  • - Accelerator drive failure.

Check the stroke of the accelerator pedal, the gap in the drive (free play of the pedal), make sure there are no jamming parts, replace defective parts, lubricate the cable with engine oil

- Faulty or misadjusted carburetor starter or drive.

See "The power supply system of the ZMZ-402 engine." Adjust starter, replace worn parts

  • - Incorrect ignition timing See "Ignition installation GAZ-3110" Adjust the ignition timing
  • - One ​​(usually TPS) or several sensors of the engine control system or their circuit are faulty. The indicator lamp KMSUD is on.

Diagnostic codes can pinpoint the problem. Check the sensors and their circuits with an autotester. Restore contact in electrical circuits, replace faulty sensors.

- The fuel pressure regulator is faulty or vacuum is not supplied to it from the intake manifold, or the fuel outlet hose (tube) is pinched.

Using a suitable tee, connect a pressure gauge to the inlet hose of the fuel rail - the fuel pressure in the rail should be no more than 3.2 kgf / cm2 at idle.

If not, check if vacuum is being supplied from the inlet piping to the regulator. Check and bleed fuel lines. Replace the defective regulator, tubes, eliminate the kink in the hose, restore the integrity of the air line

- Excessive fuel level in carburetor float chamber. There is a strong smell of gasoline from the exhaust pipe, a cold engine starts better than a hot one.

Remove the top cover of the carburetor, check the tightness of the float, its ease of movement and the absence of touching the walls of the float chamber,

Checking the tightness of the needle valve: after removing the carburetor cover and pulling the float up with your finger, pump gasoline with the fuel pump lever. The slightest leak of gasoline from under the needle or valve seat is unacceptable.

Replace leaky needle valve, adjust float chamber fuel level

  • - Clogged idle air jet (Inspection) Flush with unleaded gasoline or acetone and blow out the jet. If heavily soiled, clean it with a fishing line or a soft wood needle (toothpick). Flush the crankcase ventilation system
  • - Re-enriched mixture due to gasoline leaking into the crankcase through a torn fuel pump diaphragm. The oil on the dipstick smells like gasoline, at idle the low oil pressure lamp may light up.

Replace the fuel pump or its diaphragm; if there is a lot of gasoline in the oil, then the oil

  • - Leaking injectors (overflow) (Check injectors) Replace defective injectors
  • - Second carburetor chamber throttle/throttle not fully closing. The gap between the throttle valve and the walls of the mixing chamber / throttle assembly is visible through the light.

Use the damper stop screw until it closes completely. At the same time, the damper should open easily, without jamming. After adjusting the screw heads, fill with paint

  • - Carburetor chokes are mounted on skewed axles and therefore won't close (Inspection) Replace carburetor
  • - Foreign object under throttle (Inspection) Remove foreign object, check throttle
  • - The idle speed controller or its electrical circuit is faulty

Substitute a known-good regulator. Replace faulty regulator

In cold weather, the engine stalls shortly after driving,but restarts after a short stop:

- An ice plug has formed in the carburetor diffuser (the heated air supply hose is not connected to the outlet on the exhaust manifold) (Inspection) Clamp the hose on the heated air intake.

In hot weather, the engine stops spontaneouslyand is difficult to start:

- Steam plug in the fuel system. Inspect the fuel lines, blow out the fuel line with a tire pump. Eliminate kinks in hoses, replace deformed tubes

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The lubrication system diagram is shown in Fig. 1. Oil pressure in the lubrication system of a warm engine at low crankshaft speed 550–650 min -1

In the article we will consider possible malfunctions of the front axle of the UAZ-3151