If your car has trouble starting but runs fine after startup. Regrettably, this could be the result of a wide variety of reasons. There’s nothing quite like the prickly panic of starting your car and nothing happens. Immediately followed by the overwhelming feeling of relief once it starts up and drives normally.
I drove a car like that. Once I got it started, I was afraid to turn it off for fear it may not turn on again. That’s no way to live. So, I wound up getting rid of it. If you’re experiencing this issue, here are a couple of reasons why this could be happening.
1. Weather Conditions
I say this knowing very well that I’m likely in the minority here. But I do enjoy the crisp, cold snap of winter. But wintery weather conditions can absolutely affect your car’s ability to start.
Cold weather causes the engine oil, antifreeze, transmission fluid and other important fluids that your car needs to thicken, preventing them from flowing freely. Also, worn fuel and brake lines can allow moisture in causing fluids to freeze and create blockages that keep your engine from firing up.
Plus, cold weather increases electrical resistance which makes it harder for the battery and spark plugs to do their job. But then as your car warms up from your attempts to start it. The engine will usually turn over and begin to run normally.
2. Faulty Ignition Switch
Another reason why your car has trouble starting but runs fine after it fires up could be due to a faulty ignition switch.
A bad ignition switch won’t be able to supply enough power to the starter motor, ignition system and other engine controls necessary to get your car started. The ignition switch is responsible for activating nearly all the electrical systems in your car.
Symptoms of a bad ignition switch can include:
- a silent starter mode,
- flickering interior lights,
- dashboard lights that turn off momentarily,
- and ignition keys that get stuck in the ignition switch.
I experienced dashboard lights that would turn off randomly and turn back on by themselves in my Nissan Maxima.
3. Bad Neutral Safety Switch
When I first started college, I had a ten-year-old Nissan Sentra that developed issues with a bad neutral safety switch.
Anxious to get to class on time, I would twist the key in the ignition… and nothing happened. I discovered that by shaking the transmission the car was able to start just fine.
The job of the neutral safety switch is to prevent a car from starting in any other gear but Park or Neutral. Without a neutral safety switch, a car could lunge forward or backward unexpectedly. A bad neutral safety switch or an ancillary support system connected to it might be the reason why your car has trouble starting but runs fine afterward.
4. Clogged Fuel Filter
One of the most common signs of a clogged fuel filter is an engine that won’t start. Typically, a clogged fuel filter won’t allow the engine to start at all. But if it’s beginning to get gunked up, you’ll experience ignition startup difficulty that gets so bad you won’t be able to start the car up at all.
A strong odor from the exhaust pipe is one sign of a fuel pump that needs changing. To prevent this from happening to you, the fuel filter should be changed every five years or 50,000 miles. But many mechanics suggest changing it every 10,000 miles due to its scope of responsibility.
5. Problems with Spark Plugs
The reason why your car has trouble starting but runs fine after it starts may have nothing to do with an empty gas tank or dead battery.
If your spark plugs can’t produce enough spark to start the car, you’re not going anywhere. Besides difficulty starting, other symptoms of failing spark plugs include:
- Reduced gas mileage,
- Lack of acceleration,
- Engine misfires, and
- Rough idling.
A good spark plug is clean with no damage to the electrodes. A bad spark plug is covered in oil, fuel and/or carbon. It could also be blistered from running too hot.
6. Issues with the Starter Motor
If you try to start your engine but all you hear is a clanking or clicking noise each time you turn the key or push the start button. But then after a few tries the engine starts up and begins running smoothly. There’s likely an issue with a key part of the starter motor.
Starters are powerful electric motors used to start a car’s engine. But like any other part of a car, starters wear out and fail over time.
Other signs of a failing starter motor include:
- Smell of smoke,
- A starter motor that’s covered in oil,
- Interior lights that dim when starting the car,
- A grinding noise when the car starts or runs,
- Starter keeps running after the engine is started,
- Engine whining or whiring without cranking over.
7. Problems with the Battery
A faulty battery can not only give your car trouble to start. But it can also affect the performance of the starter and alternator. It can be challenging to distinguish if the reason why your car is having issues starting is because of the starter or the battery.
But one way you can tell is by jump starting your car. If it’s just a bad battery, then your car will start right up with a jump start. But if the issue lies with the starter motor, then you might be able to get the motor started with jump start. But once you remove the jump start cables, the motor dies.
8. Faulty Fuel Pump
A fuel pump is necessary to get gasoline from the fuel tank to the engine. But if the fuel pump can’t get gas from the tank to the engine, then you’ll experience some trouble with starting your car even though it’s able run fine on its own once started.
Fuel pumps get warn overtime. When that happens, it won’t have enough pressure to push enough gas from the tank the engine and the engine will struggle to start.
If engine temperatures have been very high, this is a good reason why your fuel pump could be failing. Allowing the engine to cool down a bit will allow the fuel pump to reset without the need to add additional pressure for the engine to start it.
9. Loose Connections and Leaks
A vehicle relies on a series of interrelated parts working together harmoniously. Loose connections and leaks can cause interruptions to important systems required to start your car, even though it might run well once started.
Electrical contacts necessary to provide power to the starter motor wear down over time due to use. This means less and less power is transferred to the starter motor, which is why you’re experiencing a slow start.
An engine needs a precise mix of air and fuel to fire up and run properly – all of this is controlled by the ECU. But a vacuum leak can allow unmetered air into the engine throwing off the balance of the air to fuel mixture and causing your car to have difficulty starting.