What are the reasons for the car not accelerating when the throttle is fully pressed?
3 Answers
When the throttle is fully pressed, the speed does not increase. The engine operates basically normally under no-load conditions, but accelerates slowly under load, lacks power when going uphill, and still feels insufficient power when the accelerator pedal is fully pressed. The engine speed does not increase, and the maximum speed cannot be reached. These are all signs of insufficient engine power. The reasons for insufficient power are as follows: 1. Clogged air filter; 2. Improper throttle adjustment, unable to fully open; 3. Low fuel pressure; 4. Clogged or poorly atomized fuel injectors; 6. Faulty air flow meter; 7. Incorrect ignition timing or weak high-voltage spark; 8. Low engine cylinder compression pressure.
I've fixed the issue of the car not accelerating when the throttle is fully pressed many times before. The most common cause is a problem in the fuel system, such as a faulty fuel pump leading to insufficient fuel supply, making the car as powerless as a thirsty camel; or clogged fuel injectors causing uneven fuel spray and an imbalanced air-fuel mixture, which hinders acceleration. Another frequent issue is ignition problems, like worn-out spark plugs or faulty ignition coils, where the spark fails to ignite properly, naturally making the engine weak. When the mass airflow sensor malfunctions, it miscalculates the air intake, leading to poor fuel combustion, which also prevents the car from speeding up. I recommend paying regular attention to fuel system maintenance, timely replacement of filters, and checking fuel pressure. If this problem occurs on the highway, safety comes first—pull over and inspect the vehicle.
I remember once driving long-distance, pressing the accelerator to the floor but the car was still crawling, which really drove me crazy. Later, I found out it was a transmission issue—the torque converter in the automatic transmission had failed, and the clutch was slipping, so power couldn't reach the wheels at all. Manual transmission cars can experience similar problems if the oil level is low or the oil is dirty. Check the transmission fluid to see if it's cloudy or has a burnt smell, and replace it promptly if needed. Don't slack on regular maintenance—use the manufacturer-recommended oil and develop good habits to avoid many unexpected issues. If you encounter trouble on the highway, don't force it—slow down, pull over safely, and then fix it gradually to prevent bigger failures.
