What Causes the Speed and RPM Not to Increase When the Accelerator is Fully Pressed?
3 Answers
Car accelerator pedal, intake system, fuel system, ignition system and other failures can all cause the speed and RPM not to increase when the accelerator is fully pressed: Car accelerator pedal failure: If the throttle position sensor is dirty or the voltage is unbalanced, it will cause electronic throttle failure, resulting in the speed not increasing when the accelerator is fully pressed. It is necessary to check the fuel pressure, cleanliness, and replace the fuel filter. Intake system failure: The engine needs sufficient air to work properly. If there is air leakage or blockage in the intake system, the car will experience reduced power, RPM not increasing, and body shaking when accelerating. It is necessary to check the ignition system, cylinder wires, spark plugs, etc.; check the cylinder pressure to see if the engine is missing cylinders; check whether the intake and exhaust pipes are unobstructed (catalytic converter blockage). Fuel system failure: If poor-quality gasoline is used, it can cause the fuel pump to burn out, catalytic converter failure, piston failure, etc., directly affecting the engine power, and easily causing the engine to stall, unable to accelerate, and RPM not increasing. It is necessary to check whether the gasoline quality is poor and replace it with better-quality gasoline in time. Ignition system failure: Ignition high-voltage wires rarely have problems. The main problems are in the ignition coils and spark plugs, as they are consumable parts. When the spark plug performance declines or inferior spark plugs are used, it will cause the car to accelerate weakly, shake when accelerating, and RPM not increasing. It is necessary to replace them with better-quality spark plugs in time.
I've encountered the situation where the car doesn't respond when the accelerator is floored several times while helping friends. Usually, it's either the engine lacking sufficient power or the transmission slipping. The most common issue is with the fuel system, such as a faulty fuel pump or clogged fuel injectors, preventing fuel from reaching the engine, which naturally prevents the RPM from increasing. Next, check the ignition system; old spark plugs or a bad coil can cause failure to ignite, leading to a sharp drop in power. It could also be due to restricted air intake, such as a dirty throttle body or an air filter that hasn't been changed for too long, causing insufficient air intake and the engine struggling to breathe. For automatic transmissions, consider issues with the torque converter; unstable oil pressure can fail to drive the wheels. Additionally, clutch wear in manual transmission cars often results in a similar symptom, where pressing the accelerator feels like a weak response. These hidden problems can all affect speed acceleration. The key is to first check simple areas, like replacing the air filter or spark plugs. If that doesn't work, take it to a professional repair shop immediately to avoid the danger of stalling on the road.
I encountered the same issue last time I drove myself, and it was so frustrating! I pressed the accelerator to the floor, but the tachometer didn't move, and the speed didn't increase. The engine roared, but it just wouldn't perform. Based on my experience, it's likely that the fuel pump failed, causing insufficient pressure to supply fuel, which paralyzed the system. Alternatively, the transmission control module might have malfunctioned, leading to sluggish shifting or even failure to upshift. If there's a crack or leak in the air intake pipe, or if the throttle position sensor is faulty, the computer won't receive accurate signals and will limit power. Carbon buildup in the engine, causing valves to stick and preventing air intake, is also a common factor. When this happened to me on the highway, it nearly caused an accident. I immediately pulled over to inspect the car—safety first. In short, don't force it to drive. Pull over safely first, check if the fuses and connectors are loose, and if that doesn't work, call for roadside assistance and get it repaired. Regular maintenance of filters and engine oil can prevent many such issues.
