Updated at: 14-07-2022 - By: Lucas

Starting a car can be a challenge for some drivers, and these issues are more common in colder climates with diesel engines, which are more susceptible.

The causes of hesitation in starting a car depend on the type of engine it has, as gasoline engines have a different problem than diesel engines. In addition, we must take into account the circumstances in which the automobile stalls, such as when the engine is warm or cold, the car has been parked for a short or lengthy period of time.

In this post, we’ll go through some of the most common causes of a slow engine start. Most cars can be started with just one or two rotations of the starter shaft. If this isn’t possible, it’s a good idea to keep an eye out for any prospective issues.

The battery is worn out.

Car Hesitates To Start

When the battery is close to fail, the engine won’t get the energy it needs to start properly, resulting in a difficult start or no start at all. In the winter, this is a common occurrence, and it can happen frequently.

A voltage drop during startup is the likely cause of the car’s inability to start, despite the starter seemingly turning. This cannot be provided by an outdated or failing battery. On a cold engine, this does not occur.

Even a brand-new battery can be drained by electrical leaks in the vehicle’s electrical system. Alarms, radios, cameras, and other electronic devices that are linked to the electrical system all have the potential to trigger this problem. The first thing you should do is check for leaks in these areas.

The spark plugs are bad

Spark plug failure is a typical cause of an automobile that won’t start. If the ignition system’s electrical connections are faulty or the ignition coil is malfunctioning, this can occur.

Spark plugs need to be replaced if you notice any issues.

Low-quality gasoline

If you fill your tank with subpar fuel, you could be inviting more trouble than you realize. Spark plug failure, clogged injectors, and even engine damage might result from erroneous detonation caused by this.. Adding fuel additives may assist if you’ve been using low-quality gas and your automobile has been having trouble starting.

Problems with the air filter

The air filter might cause the car to be hesitant to start, especially if the engine is not getting enough air. Most of the time, a blocked or unclean air filter is to blame for this problem. But the main culprit is the air filter. This is a condition that occurs more frequently in the winter months due to the drastic temperature swings.

Air leaks

Warm air is required for starting an automobile in cold weather; cold air is required in hot weather. Before that, the ECU opens the idle air control valve depending on temperature readings. A hard start may occur after a few attempts because the ECU uses air values stored in its memory and is therefore unaware of any additional air.

You should inspect the intake for air leaks in this situation. Crankcase ventilation valves and deteriorated gaskets found between the intake manifold and the engine are the most common entry points for these parasites.

A bad camshaft position sensor

Engine control units (ECUs) adjust the ignition timing and cylinder firing order using data gathered by camshaft position sensors. The engine will not start the first time if the camshaft position sensor gives an inaccurate signal. The sensor itself is not always at fault; more often than not, it is the result of improper installation and wiring. The smell of gasoline is a significant indicator of a malfunctioning camshaft position sensor.

A bad crankshaft position sensor

Because the engine can run without the crankshaft position sensor, the car will still start, but it will take longer. When a crankshaft position sensor fails, it’s often because of metal buildup on the sensor, and cleaning it solves the problem quickly and easily. This substance can be used to clean.

Bad or failing purge valve

Car Hesitates To Start-2

The purge valve’s job is to keep the atmosphere free of fuel vapors produced in the fuel tank. The intake manifold and engine cylinders can be contaminated with fuel vapors if the valve fails or leaks.

Because of this, the engine will be hesitant to start or have a difficult start on the first try because of an excess of fuel. When this happens, the idle speed may dip or hover in the middle of the range.

A bad starter

It is possible for a car to start slowly even though the battery is in good condition if the starter is defective.

Low compression in diesel engines

Cylinder piston wear is a common cause of this problem. During operation, the engine will accumulate carbon deposits, sludge, and varnish contaminants. Carbon deposits in the compression rings will eventually prevent them from working properly, and this is an inevitable part of the process. Compression decreases, and the fuel mixture cannot be ignited.

It is essential to do an engine flush in order to remove the carbon buildups before things get worse. This product is perfect for that because it gets the job done well.

The electronic control unit (ECU) might not work properly

Because of this, your car may be hesitant to start. This issue can arise if the ECU is malfunctioning, however this is an uncommon occurrence.


There are a variety of possible causes for a difficult start. You can take preventative actions such as periodically checking your car’s battery and replacing it if you discover that your car has trouble starting in the cold. When performing maintenance on a vehicle’s electrical systems, evaluate the state of the circuits, clean them as soon as possible, and use protective gear.

Check the sensors, especially the camshaft and crankshaft sensors, for functionality and condition. When the engine is heated, it can be difficult to start because of the wrong operation of these devices. Visit a reputable auto repair shop to have the part replaced. That’s the way it should be.