
Excelle's inability to accelerate when stepping on the gas pedal may be due to excessive engine oil, overly viscous engine oil, malfunctioning sensors around the engine, or faults in the transmission system. Below is a partial introduction about the gas and brake pedals: 1. Gas pedal: The gas pedal, also known as the accelerator pedal, is part of the car's fuel supply system. By controlling the amount of pedal depression, it regulates the throttle opening of the engine, controls the intake air volume, and the computer adjusts the fuel amount, thereby controlling the engine's speed. 2. Brake pedal: The brake pedal is the pedal that limits power, i.e., the pedal of the foot brake (service brake), used for deceleration and stopping. It is one of the five major operating components in car driving, with very high frequency of use. How the driver controls it directly affects driving safety. Brake pedal operations include: gradual braking (i.e., anticipatory braking), emergency braking, combined braking, and intermittent braking.

When I drove my old Excelle, I also experienced sluggish acceleration. The common causes are just a few: if the fuel pump doesn’t supply enough fuel, you can’t speed up even when flooring the throttle—my friend’s car had this issue, and it was fixed after replacing the pump; a clogged air filter restricts airflow, making the engine weak; if the fuel injectors are clogged and fuel spray is uneven, throttle response becomes very sluggish; clutch slippage causes RPM to rise without a corresponding increase in speed, a common issue in older manual cars; and a blocked exhaust system or a faulty catalytic converter can also choke the engine. Oh, and a dirty fuel tank clogging the pump’s filter screen is another possibility—these are all real cases I’ve encountered while repairing cars.

I remember my neighbor, Master Zhang, who has been repairing cars for twenty years, said that the Excelle's lack of acceleration is mostly due to these issues: air leaks in the fuel supply line or insufficient fuel pressure can lead to inadequate fuel injection; aging ignition coils causing misfires, making the car jerk and accelerate weakly; a clogged catalytic converter makes the engine feel like it's running with a mask on; the most easily overlooked issue is a stuck brake caliper, which is like driving with the brakes on; vacuum tube leaks can also disrupt the air-fuel mixture. He suggested first reading the fault codes, then checking the fuel pressure, and finally testing the cylinder pressure, especially for older cars, these checks are crucial.

Just helped my cousin troubleshoot the acceleration issue with his 2008 Excelle. Found that the most common culprits are spark plugs: electrode erosion or excessive gap causing poor ignition; leaking high-voltage wires leading to cylinder misfires; the EGR valve stuck in the open position; fuel filter not replaced for too long causing insufficient fuel supply; or a faulty oxygen sensor making the ECU miscalculate fuel mixture. Especially in older cars, wiring tends to deteriorate, and a loose crankshaft position sensor connector can also cause sudden speed drops. Last week, his car had a faulty EGR valve - the exhaust made popping sounds and acceleration was weak, but it ran fine after replacement.

On car repair forums, Excelle owners often complain about acceleration issues, and several common experiences have been summarized: Poor fuel quality can lead to carbon buildup in the fuel injectors; Worn clutch plates cause engine RPM to surge without a corresponding increase in speed; A faulty camshaft position sensor is most prone to misdiagnosis; Data drift from the intake manifold pressure sensor can cause the ECU to miscalculate; Upsizing tires can lead to discrepancies between the speedometer reading and actual speed. One particularly interesting case involved a driver discovering that the floor mat was obstructing the accelerator pedal—a simple oversight that can also cause acceleration difficulties.

My car repair mentor once said that dealing with slow acceleration in an old Excelle requires different approaches depending on the situation: weak acceleration when the engine is cold might be due to a faulty coolant temperature sensor, while weak acceleration when the engine is hot suggests checking the oxygen sensor. Slow acceleration on flat roads primarily calls for inspecting the intake system, whereas poor performance uphill often points to fuel system issues. Jerking during sudden acceleration indicates checking the ignition system, while sluggish response during gradual acceleration suggests examining the exhaust for blockages. There was a unique case I encountered: a blocked fuel tank vent created negative pressure, preventing the fuel pump from drawing fuel and causing stalling at high speeds. Regularly replacing the air filter, cleaning the throttle body, and using fuel additives can prevent many acceleration-related problems.


