What to Do When the Engine Fails to Shut Down?

[StAriel]

Engine failure to shut down may be caused by incomplete power cut-off to the shutdown solenoid valve, key switch sticking, damage to the shutdown solenoid valve, or deformation of the lever. It could also be due to sticking of the unit pump or the engine governor rack sticking or deforming. Below are the steps to troubleshoot the engine shutdown issue: 1. Starting Circuit: Check that the starting circuit is properly powered and the ignition key switch is not sticking. 2. According to customer feedback and on-site testing, the roller operates without speed drop and manual shutdown is normal, which proves that the unit pumps in each cylinder are not sticking. 3. Shutdown Solenoid Valve: After replacing the shutdown solenoid valve with a new one using the correct installation method and testing with power, the engine still fails to shut down automatically. 5. Engine Stop Lever: If the engine stop lever feels insufficiently elastic when moved, it may indicate that the engine governor rack is sticking or deformed, causing damage to the shutdown solenoid valve and preventing the engine from shutting down automatically.

[OCaroline]

I encountered this situation last time and was really a bit panicked. Quickly shift to P gear and pull the handbrake to ensure safety first. Upon inspection, I found that the ignition switch return spring was stuck, and there was no noticeable rebound when turning the key. Another possibility is that the steering wheel lock is pressing against the ignition switch. Try turning the steering wheel left and right before pulling out the key. A short circuit is the most troublesome, especially for cars with modified anti-theft devices, as they are prone to this issue. If all else fails, you can temporarily disconnect the negative terminal of the battery, but some cars may lose window memory after power loss and require relearning. After using these emergency methods, it's best to have a professional mechanic check as soon as possible, as continuous operation can cause significant damage to the engine.

[LaNolan]

If the engine won't shut off, immediately turn on the hazard lights and pull over. My first instinct is to check if the brake light switch is stuck, as some models' shutdown logic is tied to the brake signal. Severe carbon buildup in the throttle body can also cause the flap to stick in the fuel supply position, resulting in noticeable jerking when forced to shut down. If the anti-theft indicator light on the dashboard is flashing, it might be due to lost key chip signal causing system confusion. For vehicles with modified auxiliary fuel tanks, also consider potential fuel switching valve failure. It's recommended to bring the repair manual to the workshop—they can quickly read fault codes with diagnostic tools, while DIY attempts may lead to misjudging wiring harness connector positions.

[PaulMarie]

It's indeed scary when the engine keeps running after removing the key. First, check if the tachometer returns to zero. Sometimes the starter motor gets stuck and drags the engine, accompanied by a harsh noise. A stuck ignition relay is also common—try removing the corresponding relay from the fuse box. For older cars, pay attention to whether the positive terminal of the ignition coil is short-circuited, and be alert if there's a burnt smell. For cars with start-stop function, check if the battery voltage is abnormal. These checks take at most ten minutes. If the issue persists, don't force it—calling a tow truck is the safest option. Remember to inform the repair shop about the steps you've already taken to save diagnostic time.

[RicardoFitz]

I've handled three cases like this. First, press the brake pedal firmly and then turn the key. Some electronic power-assisted models can be turned off by hydraulic pressure relief. Next, check if the floor mat is stuck on the throttle cable—it's a basic mistake but it really happens. Focus on inspecting the ignition lock cylinder linkage under the steering wheel; sometimes tapping the housing with a screwdriver can loosen the jam. For fuel-injected cars, be aware that a stuck fuel pump relay can cause continuous fuel supply—open the hood and listen if the fuel pump is still running. If all else fails, disconnect the battery, remembering to remove the negative terminal first, then the positive. Lastly, a reminder: don't let the engine idle for more than ten minutes during the fault, as excessive temperature can damage the catalytic converter.