Why is the car lacking power?

[Winter]

The main reasons for a car lacking power include faults in the fuel system, intake system, exhaust pipe, and electrical system. More detailed information is as follows: 1. Fuel system inspection. With the engine off, loosen the fuel pump's outlet and return ports. When cranking the engine, there should normally be fuel flow, which can be compared to a functioning vehicle. If fuel flow is normal, check the injector return flow. Excessive return flow may indicate internal wear in the injector, causing slow or failed rail pressure buildup. 2. Intake system inspection. Check if the air filter is dirty or clogged, and if the filter element is an authentic part. Inspect all intake pipe connections and hoses for leaks. If necessary, check for excessive dust inside the intake pipe. Ensure the bypass valve opens and closes smoothly to guarantee sufficient air intake. 3. Exhaust system inspection. Check for signs of leaks in the exhaust manifold and ensure the exhaust manifold gasket is intact; replace if necessary. Verify that the exhaust butterfly valve opens and closes smoothly. Perform an exhaust brake action while stationary to observe the valve's movement and determine if it opens and closes fully. 4. Electrical system inspection. Here, the electrical system mainly refers to the ignition system. The electrical system generates high voltage, which is delivered via wires to the spark plugs. The spark plugs ignite the air-fuel mixture in the combustion chamber. Therefore, faulty wires or spark plugs are the most likely causes of poor ignition.