Grant 16 valves: diagnostics and repair

The situation when Lada Granta. With a 16-valve engine, it refuses to start, often catches the driver by surprise. This can happen on a frosty morning, after a long downtime, or suddenly in a parking lot by the store. Unlike the simpler 8-valve versions, the 16-valve VAZ-21127 unit is more demanding on the state of the ignition system and fuel quality, so diagnosis requires a careful approach.

The first thing to do is to assess the nature of the rejection. The engine may not respond to the turn of the key at all, the starter may spin, but flashes in the cylinders do not occur, or the engine catches and immediately dies. Understanding the primary symptoms allows you to save time and immediately eliminate whole groups of malfunctions. Ignoring primary signs Often leads to more complex and expensive repairs.

In this article, we will discuss in detail the main reasons why car-in-carWe will propose an algorithm of actions to independently solve the problem. We will consider the electrical part, the fuel supply system and software failures characteristic of 16-valve modifications.

Diagnostics of the starter and battery

If you don’t hear any sounds when you turn the key to the Starter position, or if you hear only a quiet click, the problem is most likely the electrical circuit. The most common, but common reason is discharged battery. Even if the headlights are on, the starting current may not be enough to turn the crankshaft with the required frequency.

In the case when the starter spins sluggishly, and the lights on the dashboard go out, you need to check the terminals. Oxidation of contacts is the scourge of the domestic automotive industry. Cleaning the terminals and checking the mass on the body often solve the problem. If the starter clicks, but does not twist, wear of the retracting relay or the brushes of the electric motor themselves is possible.

• 🔋 Check the voltage at the terminals of the battery multimeter - it should be at least 12.5 V.
• ⚡ Examine the terminals for oxidation and density of the attachment of the wires.
• 🔌 Check the integrity of the fuse F3 (25A) in the assembly unit.

It is important to note that 16-valve engines have slightly higher compression than 8-valve engines, so a reliable starter is required for a confident start. If you hear the characteristic crackling of the bendix, but the flywheel does not scroll, then the gear teeth are worn out. In that case, starter-up inevitable.

⚠️ Warning: If the starter is buzzing but the engine is not spinning, release the key immediately. Prolonged work of the starter under load without engine rotation can lead to melting of the retracting relay and melting of the wiring.

Problems with the ignition system and candles

When the starter turns the engine, but Granta. It is not started, most often the fault of the ignition system. The 16-valve engine is equipped with individual ignition coils for each cylinder. This increases reliability, but complicates the diagnosis: if one coil fails, the engine will triple, but if there are problems with the control module or wiring, there will be no start at all.

The first thing to do is to twist the candles. Their condition can tell us a lot. Gasoline-filled candles speak of an over-enriched mixture or sensor problems, black soda speaks of a rich mixture or engine malfunction, and white plaque speaks of a poor mixture or overheating. Candle gap It also plays a critical role: on 16-valves it should be strictly within the range of 1.0-1.1 mm.

Often drivers forget about high-voltage wires, although on modern 16-valve VAZ engines their role is performed by the coils themselves, worn on the candle. However, the contact in the coil connector may oxidize. It is also worth checking for a spark. To do this, the candle is pressed to the mass and twisted with a starter. If there is no spark, check the power on the coil.

How to check the spark safely?

Use a special discharger or an old spare wire. Do not hold the candle with your hand in a rubber glove – high voltage can break through the insulation and shock even if the glove seems whole.

Pay special attention crankshaft position sensor (DPKV). If this sensor is faulty or contaminated with metal shavings, the ECU does not see where the piston is and simply does not give a command for the spark. This is one of the most common causes of sudden failure of the start on the go or after parking.

Fuel system: pressure and injectors

The lack of gasoline in the cylinders is the second most popular reason after problems with sparks. Nana Lada Granta. a submersible fuel module is installed in the tank, which includes a gas pump, a rough cleaning filter and a pressure regulator. When you turn on the ignition, you should hear the characteristic buzzing of the pump for 2-3 seconds.

If the pump is silent, check the fuse and relay of the gas pump. They are in an additional safety lock (usually to the right of the passenger). A burnt fuse or stuck relay is a common illness, especially after engine washing or in wet weather. If the pump is humming but the pressure in the ramp is weak, it may be clogged fine-cleaner Or the net on the pump itself.

The pressure in the fuel ramp for the 16-valve engine should be 3.6-4.0 atm (excluding the pressure in the receiver at idling). You can check it through a special connection on the ramp, connecting a pressure gauge. If there is no pressure, the pressure regulator or the pump itself may be faulty.

Symptoms.	Probable cause	Action.
The pump is not humming	Fire fuse/relay.	Replace the fuse F3 (15A)
Weak pressure.	Clogged filter or net	Replace the fuel filter
Pressure's dropping.	Not keeping the regulator	Replace the pressure regulator
Knocking in the tank	Pump wear and tear	Replacement of the gas pump

Effects of immobilizer and ECU

Modern VAZ cars are equipped with a complex system of protection against theft - immobilizer (APS). If the system does not read the tag from the key, it blocks the start of the engine. In this case, the starter will spin, candles give a spark, but nozzle They won't open. On the dashboard, the indicator of the immobilizer often flashes (key machine or red LED).

A common problem is the battery discharge in the key or synchronization failure. Try using a spare key. If the car reacts to it, then the problem is in the main key chip. There may also be failures in the operation of the electronic control unit (ECU). "Glitches" of firmware can occur after voltage surges during "smoking".

To diagnose the ECU, you need to connect the OBD-II scanner. Errors can be different: from “breaking the nozzle chain” to “incorrect signal of the DPCV”. Sometimes it helps banal error reset by removing the battery terminal for 10-15 minutes, but this is a temporary measure.

⚠️ Warning: When lighting a 16-valve Grant, never remove the terminals from a working donor and do not allow a repolarization. A power surge can instantly disable an ECU, the cost of which is much higher than a battery replacement.

Mechanical problems and GRM

The worst dream of the owner of the 16-valve Granta is the break of the belt of the GRM. Unlike some older engines, here, when the pistons meet the valves, which leads to expensive repair of the head of the block. If the starter turns the engine too easily and quickly, with an unusual sound, and then you hear a metal clang - most likely, the belt is torn.

You can check the integrity of the belt by removing the plastic protective cover. If the belt is intact but the teeth are cut, the effect will be the same. It is also worth checking the tension of the belt: if it is pulled, it increases the load on the bearings of the pump and generator, if weak - it can jump on the tooth, knocking down the head of the head. gas-distribution.

With stray phases, the engine can start, but it will work extremely unstable, stall or shoot at the muffler. In this case, it is necessary to re-expose the marks on the pulleys of the crankshaft and camshafts. The procedure requires precision and a special tool.

Seasonal factors and fuel quality

In winter, the problem of “does not start” is especially acute. The 16-valve engine is sensitive to the quality of the mixture. If the gasoline contains water, it can freeze in the fuel line or filter, blocking the supply. Also, the condensation in the tank in winter turns into an ice cap.

The frost oil in the engine creates a huge resistance when scrolling. If the battery isn’t new, it may not be able to handle viscous oil. In such cases, it is recommended to use a preheater or at least warm up the battery, including light for 30-60 seconds before starting.

In the summer, the main problem is overheating and detonation. Poor-quality fuel with a low octane number can cause spontaneous ignition of the mixture, because of which the engine after turning off the ignition may twitch or not start immediately due to the “steam stopper” in the fuel ramp.

Frequently Asked Questions (FAQ)

Why does Grant 16 valves start and go down?

Most often this is due to a malfunction of the idle regulator (RXX), the sucking of unaccounted air through the gaskets of the intake manifold or a malfunction of the throttle position sensor (DPDZ). It is also worth checking the fuel pressure: if the pump pump pumps, but the regulator releases the pressure immediately after starting, the engine will stall.

Can I get Grant off the pusher?

You can start a 16-valve Grant with a pusher, but it is not recommended to do this often. When starting from the pusher, the pump of the fuel pump does not work, which can lead to local overheating, and the catalytic converter may not have time to warm up and clog with unburned fuel. Use this method only in emergency cases.

Which candles are best placed on a 16-valve Grant?

The plant recommends candles with a gap of 1.0-1.1 mm. NGK, Denso, Bosch and domestic E3s have proven themselves well. It is important to choose candles with a potassium number of 17 (GOST) or 6 (NGK / Denso). Using too “cold” or “hot” candles will lead to problems with start-up and soot.

What to do if the EBU burns?

If the diagnosis showed the death of the control unit, it can be replaced with a new or used one. However, the new block will require firmware under your immobilizer (key binding). Used unit should be searched with the same firmware number, otherwise the car may not start or work incorrectly.