Troit engine ZAZ Forza

The ZAZ Forza subcompact hatchback is equipped with a one and a half liter ACTECO SQR477F gasoline power unit, whose power is 109 hp. Each of its four cylinders has 4 valves. The electronics control the distributed injection of gasoline into the cylinders and the ignition. The gas distribution mechanism uses one camshaft with 12 cams. Each pair of exhaust valves opens with one cam, while the intake valves have a separate cam for each valve.

The SQR477F engine has good power, dynamics and efficiency characteristics. It is quite reliable, its nominal service life before major repairs is 300 thousand kilometers. The motor has good maintainability, and there are no problems with it. It is no coincidence that this unit turned out to be very popular; it can be found on many other cars. 

Despite the reliability, the engine can sometimes fail, troit, stall. With proper maintenance, serious damage to the SQR477F motor itself is quite rare. More often, the causes of unstable operation lie in the ignition system, fuel supply or faulty sensors.

The appearance of tripling requires an immediate response. Otherwise, the problem may develop further. Damage can be received by various parts of the cylinder-piston group. It is possible that as a result, an overhaul of the engine will be required. 

How does the engine trip

Trouble in the engine means that in one of the cylinders the process of combustion of the air-fuel mixture occurs abnormally. In other words, the mixture burns only partially or there is no ignition at all. In the latter case, the cylinder is completely switched off from the operation of the motor.

Naturally, the very first and most noticeable sign of tripling is a drop in power.

Another obvious symptom is a significant increase in engine vibration. Although the motor can shake for other reasons, for example, due to wear, which is not so rare for the ZAZ Forza unit.

Quite often, pops come from the exhaust pipe. Such sounds always indicate problems with the engine, but if the pops are uniform, then the normal operation of one of the cylinders is disrupted.

In addition, tripping often causes problems with starting a cold engine.

A tripling companion is also an increased consumption of gasoline. 

The engine can troit in all modes or in one, constantly or periodically.

What and how to check if the ZAZ Forza engine troit

Most often, the operation of one of the cylinders is disrupted due to malfunctions of the ignition system. It may be unadjusted, too early or too late, the spark may be weak or completely absent.

Candles

It’s worth starting with a check, if only because it’s the easiest to do. Make sure that the electrodes do not show significant wear, the insulator should not be damaged, and that its color is normal brown, yellowish or gray. A wet, blackened spark plug should be replaced immediately. 

Sometimes periodic tripling is caused by soot on a candle. In this case, cleaning the isolator may solve the problem. 

Careful inspection of the candle will indicate a possible cause of unstable operation of the motor.

Soot on the insulator indicates an enriched mixture. Check the condition of the air filter. In addition, the absolute pressure and air temperature sensor may not work correctly, based on its data, the ECU determines the ignition timing and the duration of the injector activation pulse. The sensor is located on the intake manifold.

Red deposits are usually caused by poor quality gasoline. They can cause the center electrode to short to the housing, causing misfiring.

Beige crust is also usually associated with low-quality fuel. Its formation is facilitated by the penetration of oil into the combustion chamber. Check and replace the valve stem seal on the valve guide.

If there are obvious traces of grease on the candle, this indicates a significant ingress of oil into the combustion chamber. In this case, the repair of the piston group or cylinder head shines.

Ignition module

This assembly is located on the side of the cylinder head cover on the transmission side. It produces a voltage of 34 kV, which is used to create a spark between the spark plug electrodes. A feature of the ZAZ Forza ignition module is that it consists of two primary and two secondary windings, which are connected in turn and start sparking on two candles at once.

A - common wire (ground) of the primary winding No. 1, wire color is red with a white stripe, connected to the E01 ECU contact;

B - +12 V supply for primary windings;

C - common wire (ground) of the primary winding No. 2, wire color is white, connected to the E17 ECU contact;

D - high voltage wires.

The resistance of the primary windings should be 0,5 ± 0,05 ohms. 

Remove the high-voltage wires from the candles of the 1st and 4th cylinders and measure the resistance of the secondary windings. It should be in the range of 8,8 ... 10,8 kOhm.

If possible, also measure the inductance of the windings. In primary ones, it is normally 2,75 ± 0,25 mH, in secondary ones it is 17,5 ± 1,2 mH.

High voltage wires also need to be checked. The condition of their insulation and terminals should not be in doubt, otherwise replace the wiring and check the operation of the engine. There is a way to check the wires in the dark - if they spark somewhere when the engine is running, then the voltage will not reach the candles.

Nozzles

This is the next thing to check. It is not uncommon for injectors to become clogged, especially if you use dirty gasoline and forget to change the fuel filter regularly. If a clogged injector is to blame, the problem usually becomes more noticeable during acceleration.

If the atomizer requires cleaning, this can be done with a solvent or carburetor cleaner. But in no case should the nozzle be completely immersed in the cleaner, so as not to cause damage to the electrical part. Not everyone will be able to competently clean the nozzle sprayer, so it is better to contact the service station with this problem.

Two wires are suitable for the injector connector - a signal from the E63 ECU contact and +12 V power. Disconnect the chip and measure the winding resistance at the injector contacts, it should be 11 ... 16 Ohm.

You can do it even easier - replace the suspicious nozzle with a known working one and see what changes.

Violation of the composition of the air-fuel mixture

Too much or too little air may be supplied to the cylinders. In both cases, the combustion of the mixture will not be normal, or it will not ignite at all.

The cause of air deficiency is most often a clogged air filter, less often - dirt in the throttle. Both problems are easily fixed.

It is more difficult to find and eliminate the cause of excess air in the mixture. There may be a leak in the intake manifold air duct, cylinder head gasket or other seals. Replacing a gasket is quite a troublesome task, but if you are confident in your abilities, you can purchase one for ZAZ Forza and change it yourself.

Reduced compression

If the search for the causes of tripling was unsuccessful, it remains. Underestimated compression in a separate cylinder is possible due to burnt or damaged piston rings, as well as due to a loose fit of the valves to the seats. and not excluded. Sometimes it is possible to save the situation by cleaning the cylinder from soot. But, as a rule, reduced compression leads to a serious repair of the power unit.

Well, if everything is in order with compression, but tripling is still present, then we can assume that there are errors in the operation of the electronic engine control system, including numerous sensors and actuators. Here it is unlikely that you will be able to cope on your own, you will need computer diagnostics and the help of specialists.