What is the reason for the engine stalling like fuel supply failure during cold start?
3 Answers
The reasons for engine stalling, shaking, and inability to accelerate during cold start are as follows: Reason 1: The spark plug loses its ignition capability. Reason 2: The throttle valve malfunctions. Reason 3: Carbon deposits can cause incomplete combustion of gasoline, leading to engine shaking issues. Engine carbon deposits have significant impacts on vehicles, primarily reducing engine power, which means uneven power output and gradual attenuation—in other words, the engine becomes increasingly weak. Secondly, it increases fuel consumption, adding to the economic burden. Reason 4: Difficulty in starting the engine, making it hard to ignite. Severe carbon deposits in the combustion chamber can also cause cylinder knocking, noise during low-speed acceleration, damage to the piston and crankshaft, and engine overheating, which can seriously affect vehicle safety.
I have dealt with numerous cases of cold start stalling, with the most common cause being insufficient fuel supply from the fuel system. In cold weather, increased fluid viscosity leads to inadequate fuel pump pressure, especially in older vehicles with worn fuel pumps or excessive tank impurities. Additionally, spark plug carbon buildup or wear reduces ignition performance, causing improper air-fuel mixture and stalling. Idle control system issues, such as a stuck stepper motor, can fail to maintain cold start RPM. Faulty temperature sensors may mislead the ECU into incorrect adjustments. Other possibilities include severe valve carbon deposits or fuel line leaks. Recommended first steps: check fuel pressure, replace the oil filter, and clean the throttle body. If unresolved, consult a professional technician to prevent long-term engine damage and ensure driving safety.
My car also once stalled suddenly during winter startup, which was quite concerning. The main issues were insufficient fuel supply, such as an aging fuel pump or clogged fuel lines, where oil flows poorly when cold; problems with the ignition system like faulty spark plugs or leaking high-voltage wires, causing weak ignition; and a dirty or stuck idle control valve, causing the RPM to drop quickly after startup. Excessive carbon buildup in the intake manifold is also common. When the environmental temperature is low, it's best to let the car warm up for a minute or two before driving. Checking these components isn't difficult—I replaced the spark plugs myself and the problem was resolved. Don't ignore it; get it repaired as soon as possible to ensure reliable driving.
