What are the reasons for being unable to start the engine even with a jump start?

[StKyle]

The reasons for being unable to start the engine even with a jump start can be categorized into rescue issues and problems with the vehicle being rescued. Below are the details: 1. Rescue issues: If a vehicle is left unused for a long time, the battery will gradually discharge naturally, leading to a dead battery and the inability to start the vehicle. In such cases, jumper cables are needed to start the vehicle. However, there are instances where even with a jump start, the vehicle fails to start. This could be due to rescue issues, such as the jumper cables being too thin, resulting in insufficient current; improper operation during the jump start, where the cables are not securely connected or the rescue vehicle is not running, leading to insufficient voltage and current. To address this, it is essential to ensure that the rescue vehicle has adequate voltage and current and to use compliant jumper cables with standard procedures. 2. Problems with the vehicle being rescued: The battery of the rescued vehicle may have been drained multiple times, rendering it incapable of holding a charge and severely damaged. Alternatively, the rescued vehicle might have other starting-related issues besides insufficient voltage and current, such as flooded spark plugs from failed attempts to start, or a malfunctioning fuel pump that prevents the vehicle from starting. In such cases, it is necessary to seek assistance from a professional repair service for rescue and repair, or to tow the vehicle to a relevant repair facility for troubleshooting.

[CoraAnn]

I've encountered similar issues before – jump-starting the car but it still wouldn't start, which is really frustrating. There could be several reasons: first, the battery might be completely dead beyond recovery; second, the starter could be stuck or broken, preventing current from reaching the engine; third, there might be electrical circuit problems like loose/corroded wiring connections or blown fuses; fourth, fuel system failures such as a malfunctioning fuel pump or empty tank. Sometimes mechanical engine issues like insufficient cylinder compression can also cause this. Safety comes first – if it doesn't work after a few attempts, don't force it. Call a tow truck immediately for professional repair. For maintenance, I recommend regularly checking battery condition and terminal cleanliness – don't wait until problems arise.

[Shelly]

After years of driving, it's common to encounter jump-start failures. Often it's due to a worn-out starter motor, where internal coils or contacts are burnt out, preventing proper current flow; short circuits or broken wires may also cause no response after jump-starting; or a clogged fuel filter restricting fuel supply and causing starting difficulties. I recall one instance where extremely low temperatures caused the engine to freeze, affecting ignition. It's advisable to first check if the jump-start connections are correct—ensure positive and negative terminals aren't reversed; then gently tap the starter motor to try. If that doesn't work, stop immediately to avoid damaging the battery. Regular maintenance is crucial—replacing the battery proactively can prevent issues.

[DiBlakely]

This is really frustrating and poses significant safety risks. If the car still won't start after a jump, the cause could be a complete failure of the starting system, such as a bad relay or failed coil; or the fuel pump isn't working, cutting off fuel supply to the engine. In extreme cases, engine compression failure could also be a factor. In such situations, don't risk trying further—turn on the hazard lights, stop, and call for help to avoid causing bigger problems. It's best to have a professional technician diagnose the root cause. As a preventive measure, get into the habit of testing the battery voltage every few months.