If the relay has an internal short it may keep power fed to the ignition and fuel system, even when ignition cylinder is in another position, or the key is removed. This will cause the fuel pump and ignition components to remain powered on, drawing current, at all times, which will eventually lead to a dead battery. Click to see full answer.
Can you jump start a car with a bad fuel pump?
Jump starting due to a bad battery will not make a bad fuel pump start working. I would recommend replacing a bad battery and then doing a thorough diagnosis of the fuel system to diagnose the fuel pump not working.
Can a bad fuel pump cause car to die?
Dead Engine
If the fuel pump gets clogged or dies, it cannot transfer gas to the engine. When this happens, you won't be able to start your car, truck, or SUV at all. The problem could also be clogged fuel lines.
When a fuel pump goes bad what happens?
A faulty pump with low pressure will disturb the engine's air-fuel ratio, which can cause all sorts of performance problems. Aside from hard starting, the vehicle may experience misfires, a loss in power and acceleration, a decrease in fuel efficiency, and even engine stalling.