
The causes of poor engine acceleration are: 1. Incorrect ignition timing; 2. Low fuel pressure; 3. Air leaks in the intake system; 4. Faulty throttle position sensor or air flow meter; 5. Poor injector performance; 6. Malfunctioning exhaust gas recirculation system; 7. Weak ignition signal. The function of the engine is: to convert the thermal energy of gasoline or diesel into mechanical energy by burning the fuel in a sealed cylinder, causing the gas to expand and push the piston to perform work. Engine maintenance methods: 1. Use qualified engine oil; 2. Use qualified coolant; 3. Regularly clean the radiator scale; 4. Regularly remove carbon deposits from the engine.

Recently, I always feel like my car has no power when accelerating. After taking it to the repair shop for inspection, I found out there were quite a few issues. The most common problem is with the fuel system – either the fuel pump is old and can't supply enough fuel, or the fuel injectors are clogged with carbon deposits, just like my 80,000-kilometer-old car. Another issue could be with the ignition system, where the spark plug gaps are too wide or the ignition coils are aged, causing incomplete fuel combustion. It might also be that the air flow meter is covered with dust, preventing the engine from taking in air, or the catalytic converter is clogged, making it hard for exhaust gases to escape. Even a faulty throttle pedal sensor can cause this, and more seriously, internal engine air leaks or improperly closing valves. You shouldn't ignore this problem – last time I drove for half a month like this and ended up paying over 4,000 yuan for repairs.

Over the years of repairing cars, I've dealt with numerous cases of acceleration weakness, which typically stem from four or five common causes. In the fuel system, a gasoline filter that hasn't been replaced in three or four years can clog, and poor fuel injector atomization is also frequent. Among ignition issues, high-voltage coil leakage accounts for about 30%, while spark plug erosion is relatively rare. The intake system requires special attention to throttle carbon buildup and vacuum tube leaks—last time, a cracked intake pipe caused an overly lean air-fuel mixture. Electrical control system failures are becoming more common; for instance, a faulty crankshaft position sensor can disrupt ignition timing, and oxygen sensor data drift can cause the ECU to misfire fuel injection. Mechanical failures are less frequent but can be troublesome when encountering issues like aging valve seals or piston ring wear. If you notice acceleration lag, promptly read the fault codes to avoid situations like my neighbor, who ended up damaging the turbocharger.

As a veteran driver with over 30 years of experience, I've seen countless cases of engines struggling for breath. With new cars, it's mostly fuel quality issues – using substandard gasoline can cause this. For older vehicles, component wear is more common. Take my 200,000-kilometer old Passat for example – last year it had acceleration jerks because the fuel pump's carbon brushes were worn flat. Pay special attention in winter when temperatures drop: engine oil that's too viscous can drag down performance. If the throttle feels heavier when running the AC in summer, it might be due to excessive compressor load. Here's a little tip: stop-and-go city driving tends to cause carbon buildup in the throttle body, while flooring it on the highway for a few minutes can actually help. But if the check engine light comes on, don't be like my son-in-law who messed around blindly and ended up wasting money.

Modifying car enthusiasts dread poor acceleration the most, especially after tinkering with wiring and intake/exhaust systems. Last week at track day, I fell victim to this—couldn't reach top speed on the straight. Mechanically, check if ignition timing is correct and whether the reinforced clutch is slipping. For fuel system, verify sufficient fuel pressure and inspect if the return valve is stuck. Intake modifications are most problematic—dirty air filters or mismatched intake pipe diameters can be fatal. If ECU was flashed, extra caution is needed as flawed programming may cause abnormal boost pressure or air-fuel ratio imbalance. Stock street cars are simpler—just remember regular air filter and spark plug changes, plus using proper gas station fuel. Don't repeat my mistake of mixing different octanes to save money—it clogged all my injectors last time.

To address engine acceleration weakness, a step-by-step troubleshooting approach is recommended: First, inspect the ignition system by removing spark plugs to check for carbon buildup or gap issues. Second, examine the fuel delivery system by testing whether fuel pressure meets standards. Third, investigate the intake system, checking the air filter and throttle opening. However, in modern vehicles, about 80% of such issues stem from electronic control components. For instance, last Thursday in our workshop, out of four vehicles with acceleration problems, three were diagnosed with faulty sensors. A defective camshaft sensor can disrupt ignition timing, while an abnormal mass airflow sensor causes the ECU to miscalculate fuel injection. Oxygen sensors contaminated by toxins provide inaccurate signals, often evidenced by blackened exhaust pipes. The most troublesome issue is wiring degradation, where engine compartment heat causes harnesses to become brittle and crack. We strongly recommend using a diagnostic scanner to read data streams early on—this method proves far more accurate than the traditional reliance on experiential guesswork.


