What to Do When a Gasoline Engine Starts and Then Stalls?
3 Answers
This situation is usually caused by inflexible governor gears, overly thick engine oil, partial blockage of the carburetor, or poor valve train performance. If there is insufficient lubricating oil in the gasoline engine crankcase, it needs to be topped up. If the carburetor is clogged, clean it with compressed air. Below is relevant information: 1. Causes of this issue: Impure gasoline or the presence of water or other impurities in the fuel tank can allow the engine to start at idle but cause unstable engine speed when accelerating, leading to stalling if the throttle is opened further. 2. Solutions: Clean the fuel tank and replace it with higher-quality gasoline. For models equipped with an oil alarm, ensure the oil level is adequate; otherwise, this issue is prone to occur near the minimum critical level. Severe carbon buildup on the piston and cylinder walls, leading to poor compression, requires complete disassembly and cleaning.
I've been driving for twenty years and have encountered the issue of the engine stalling right after ignition multiple times. This problem needs to be checked step by step: first, feel the exhaust pipe for any moisture. If there's none, it's most likely a fuel supply issue. A stuck fuel pump pressure relief valve can cause insufficient fuel injection, especially common in older cars. If the spark plugs are soaked in oil, it can make the air-fuel mixture too rich. Also, check for carbon buildup on the throttle body; if it's as thick as a rice crust and blocks the intake valve, and the idle control valve is dirty, it's like a sleeping security guard not doing its job. The most easily overlooked issue is the crankshaft position sensor—if it has poor contact, the ECU will simply stop working. It's recommended to test the cylinder pressure when the engine is cold; if the pressure difference between the four cylinders is too large, it indicates valve leakage. Actually, adding a bottle of fuel additive regularly can prevent many problems and save at least two to three hundred in repairs.
Having repaired engines for fifteen years, I've found that such faults often occur at a few critical points. If the fuel pressure can't be maintained, the fuel injection volume becomes unstable during ignition. Use a diagnostic tool to check if the oxygen sensor values fluctuate; if the reading is a flat line, it's a clear sign of air-fuel mixture imbalance. An EGR valve stuck in the open position will consume the idle air intake—try disconnecting its vacuum hose. For vacuum leaks, spray carburetor cleaner around the manifold connections to locate the leak; the engine RPM will suddenly rise at the leak point. For vehicles with variable valve timing, pay attention to the VVT solenoid valve—dirty oil can easily cause it to stick. Once, while working on a Passat, I was stumped by a demagnetized camshaft sensor magnetic ring, which failed without any warning. Nowadays, diagnostic tools can measure fuel flow rate, and within five minutes, you can tell if the fuel pump is slacking off.
