Causes of car weakness

Spark plugs are dirty and worn

Spark plugs can become clogged with soot and carbon after long periods of use or improper maintenance. Spark plugs that are clogged with soot and carbon cannot produce a spark strong enough to ignite the fuel and air mixture.

Spark plugs can also be worn, the gap between the two electrodes is large, the air-fuel mixture burns inefficiently, reducing power.

Clogged fuel filter

This is the most common cause when the engine is weak, the engine may even die in the middle of the ride, but if the vehicle is stopped for a while, it can be restarted.

Worn fuel pump or leaking pressure regulator

The fuel pump supplies fuel to the fuel tank for combustion in the engine. It also responds to the engine's needs by regulating the fuel pressure. If it fails, acceleration will be poor and the vehicle may not start.

In case of replacing the fuel filter, the injection pressure is still low, some garages often blame the pump for failure and decide to replace it. In fact, many cases are due to the pressure regulator leaking or being stuck, the fuel returning to the tank does not create pressure. The injection pressure is guaranteed but the amount of fuel entering the combustion chamber can still be lower than required. The reason is that the mass air flow sensor (MAF) or absolute air pressure sensor (MAP) reacts slowly, transmits wrong signals, the ECU controls the injector opening time is short.

Clogged exhaust pipe

An exhaust pipe consists of two filters - a muffler and a catalyst. Over time, exhaust gases accumulate in the pipe, requiring the engine to expel them with more energy. High exhaust pressure also reduces the amount of intake air, leading to power loss.

Dirty air filter

Consider this cause if your car is frequently driven in a dusty environment. If this filter is clogged or too dirty, the amount of air passing through the filter will be less, thereby consuming fuel.

Therefore, users need to clean the air filter regularly according to the schedule stated in the vehicle's owner's manual, usually every 3-6 months.

High voltage wire is faulty

The ignition coils are responsible for converting electrical energy from the battery into sparks. With a faulty ignition coil, the fuel and air mixture will not be right.

A faulty high voltage wire can also cause the engine to not fire properly, causing poor engine performance. Therefore, people need to pay attention to replace the high voltage wire if damage is detected.

Low compression ratio

This problem often occurs on vehicles that have had their oil changed infrequently or have been used for a long time. During the expansion stroke, high pressure gas leaks through the gap between the piston and the cylinder or between the valve and the base, eliminating the compression pressure on the piston.

In severe cases, oil can enter the combustion chamber and contaminate the spark plug. Engine oil also gets dirty faster. This is a serious damage that requires overhaul. To determine the exact problem, you can check by pumping compressed air into the combustion chamber through the spark plug port and measuring the pressure drop during the compression stroke (all valves of the gas distribution system are closed).

To avoid these problems, regular and periodic maintenance of the engine ignition system is very important. Car owners should follow the manufacturer's advice and instructions to maintain the performance and reliability of their car for a long time.