Can a bad battery cause a misfire? How that happens
Can a bad battery cause an ignition misfire?
Your car’s ignition system uses very little power, so a bad battery would only cause a misfire if it were so discharged that all your lights were dim and you radio wasn’t even working.
But it can cause a misfire due to dropping fuel pressure
The fuel pump uses a lot of power compared to the ignition system. And if your alternator has died and you’re running on just the battery, the lower voltage from a discharged battery could prevent the pump from maintaining the minimum fuel pressure.
That would cause a “lean fuel misfire.” Too little gas for the amount of air.
If you notice your headlights dim at a stop light, your blower motor running slower and you have a charging light on your dash, be warned that your electrical system isn’t working properly. If you continue to drive in this state, you could very well experience a misfire due to a bad battery.
©, 2022 Rick Muscoplat
Posted on by Rick Muscoplat