Reasons why a car's performance deteriorates
During use, some car owners may encounter situations where their vehicles begin to perform less efficiently and are not as powerful as before. This phenomenon can stem from a variety of causes.
Spark plugs are clogged with dust and worn out.
Spark plugs can become clogged with dust and carbon deposits after prolonged use or improper maintenance. Spark plugs heavily coated with carbon deposits cannot produce a spark strong enough to ignite the fuel-air mixture.
Spark plugs can also wear out, causing a large gap between the two electrodes, resulting in inefficient combustion of the air-fuel mixture and reduced power output.
Clogged fuel filter
This is the most common cause of a weak engine; the engine may even stall mid-journey, but it can usually be restarted after the vehicle has been stopped for a while.
Worn fuel pump or leaking pressure regulator.
The fuel pump supplies fuel from the fuel tank for the engine to burn. It also meets the engine's needs by regulating fuel pressure. If it malfunctions, acceleration will be poor and the vehicle may not start.
In cases where fuel injection pressure remains low after replacing the fuel filter, some garages often attribute the problem to a faulty fuel pump and decide to replace it. In reality, many cases are due to a leaking or clogged pressure regulator, preventing the fuel from returning to the tank with sufficient pressure. While the injection pressure may be adequate, the amount of fuel entering the combustion chamber may still be lower than required. This is because the mass air flow (MAF) sensor or the absolute air pressure (MAP) sensor may react slowly, transmitting incorrect signals, causing the ECU to control the injector opening time to be too short.
Clogged exhaust pipe
An exhaust pipe consists of two filters - a muffler and a catalytic converter. Over time, exhaust gases accumulate in the pipe, requiring the engine to expend more energy to push them out. High exhaust pressure also reduces the amount of intake air, leading to power loss.
Dirty air filter
Consider this possibility if your vehicle frequently operates in dusty environments. If the filter is clogged or heavily soiled, less air will pass through, leading to increased fuel consumption.
Therefore, users need to clean the air filter regularly according to the schedule specified in the vehicle's owner's manual, usually every 3-6 months.
The high-voltage wire is faulty.
The high-voltage coils are responsible for converting electrical energy from the battery into sparks. With a damaged high-voltage wire, the fuel and air mixture will be improper.
A faulty high-voltage wire will also prevent proper ignition, causing the engine to run poorly. Therefore, people should pay attention to replacing the high-voltage wire if they detect any damage.
Low compression ratio
This problem commonly occurs in vehicles with infrequent oil changes or those that have been in use for a long time. During the combustion and expansion stroke, high-pressure gases leak through the gap between the piston and cylinder or between the valve and seat, eliminating the compression pressure on the piston.
In severe cases, oil can enter the combustion chamber, fouling the spark plugs. Engine oil also gets dirty faster. This is a serious malfunction requiring a major overhaul. To accurately identify the 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 air distribution system are closed).
To avoid these problems, regular and consistent maintenance of the engine's ignition system is crucial. Vehicle owners should follow the manufacturer's advice and guidelines to maintain the vehicle's performance and reliability over the long term.
