Reasons Why a Car is Hard to Start After Sitting for a Few Hours - information from the the pros at Shingle Springs Subaru serving Sacramento, CA

The modern automobile is a remarkable work of engineering, and that means there are any number of reasons why your car may not start. In our authorized dealership service center at Shingle Springs Subaru, we want to help take some of the mystery out of why your car sometimes doesn't perform as it should. For instance, what if your vehicle starts right up when you turn it off for a short time to run into the store or make another quick errand but is hard to start after it sits for a longer period like overnight? This is among the more common problems we see in our Subaru service center. Below, we look at five of the most common reasons an engine won't easily start after it's sat for a while. Once you have an idea of what might be behind your car starting troubles, trust the factory-certified mechanics at Shingle Springs Subaru. We'll make sure the issue gets fixed right the first time.

Assortment of car fuel injectors

5. Carburetor vs Fuel Injection

OK, at the bottom of our list isn't as much a reason as it is an important distinction about how gas is delivered to the engine in your vehicle. We're starting here because fuel delivery is among the most common reasons for a car not to start, especially after it's sat for a while. So, if your vehicle is less than about 35 years old, you most likely have a fuel injected engine. Now, this is by no means a hard rule, but carburetors really haven't been common in new vehicles since the 1980s.

If you do enjoy your classic ride with a carburetor, you're likely familiar with it being difficult to start after it's been sitting for a while. This is typically because the gas has simply evaporated, and it takes a few turns of the engine to get gas where it needs to be. Since you probably have a modern fuel injected engine, the reason it's hard to start still relates to the fuel delivery. And we'll look closer at that further up in our list.

Jumper cables attached to car battery

4. Is the Battery Good?

When we say, "hard to start," we're talking about those times when the starter keeps turning over the engine but it doesn't start running on its own. Since the starter has enough power to turn the engine, it's mostly safe to say that the battery is good. Though, keep in mind that the battery can quickly run down if it must continually run the starter without the engine running on its own. So, if you can jump start the car, and the engine starts just fine, you should make your way to an authorized service center like ours to have an expert go through the battery and charging systems.

3. There Might Be A Problem With The Ignition System

No matter how the fuel gets to the engine, a spark is required to ignite the gas and make the engine run. Without a strong enough spark at the right time, it can be hard or even impossible for an engine to start. As with most things on your car, there are many reasons why you might not get the necessary spark. While something could be wrong with one or more of the actual spark plugs, it's more common in modern engines for something like an ignition coil to be bad. The ignition coil is essentially an amplifier to make a big enough spark to run the engine, and one of our expert Subaru mechanics can test a coil to see if it's bad.

Gas gauge showing a quarter tank left

2. Is The Engine Getting The Fuel It Needs?

Running out of gas can happen to the best of us, but you probably already know if that's why your engine won't start. Sometimes, the gas gauge can get stuck and show that the tank has more gas than it does. Also, gas in your car can expire if it sits for too long, which can also make it difficult to start your car. In a rare case, you might end up with contaminated gas from a poorly maintained gas station where water got into the supply. Unfortunately, it can be particularly difficult to determine whether any of these things are at play. To get to the bottom of the matter without delay or added expense, your best bet is to touch base with factory-trained technicians like you'll find in our Subaru service center.

1. Fuel Pressure & Fuel Pump

Today's fuel injection systems have high-pressure injectors fed by a powerful fuel pump. When everything is working properly, the fuel system remains under pressure after you turn the car off. When the fuel pump starts to go bad, that pressure will start to go away when the engine isn't running. This is one of the most common reasons that your car won't start after it's sat for many hours. In some cases, air can get into the fuel system and cause this problem, but we don't typically see that in Subaru models. Since the fuel pump is typically located inside the gas tank, replacing a bad fuel pump isn't something we recommend the average DIY mechanic dive into. Instead, give our Subaru service center a call, and we'll help get your vehicle to our shop in Shingle Springs.