As the summer causes temperatures to rise, car owners may face difficulty starting their vehicles. However, direct fuel injection solved this problem to a certain extent. That said, the car won’t start when hot due to fuel problems or a bad throttle body. Moreover, the problem can be due to the fuel turning into vapour in extreme temperatures.
Let’s go through all the reasons why your car is hard to start when warm and how to fix it.
Causes of Hard Starting When Engine is Hot
When the car engine is heated or there is a problem with the fuel injectors, it may cause car cranks but won’t start. Besides, engine overheating is not the only issue why the car won’t start. There may be underlying problems with the fuel system as well.
For instance, a vapour lock occurs when the fuel turns into gas due to extreme heat. Moreover, the car won’t start when hot due to this vapour lock. One must wait for the car to cool down before starting and driving it.
Here are all the reasons why a car takes longer to start on a hot day.
Worn-Out Spark Plugs
When the spark plugs wear out, the gap between the electrodes widens. This increased gap requires a higher voltage to generate a spark, especially when the engine is hot. If the spark is too weak, it might not ignite the air-fuel mixture properly, leading to difficulty starting the engine.
In some cases, excessive heat around the spark plug can cause fuel to evaporate before it reaches the combustion chamber. For that reason, bad spark plugs might be one of the reasons why the car won’t start when hot. Moreover, it can result in a car not starting after getting fuel because it would vaporise the fuel and cause issues with the combustion process.
While there are several symptoms of a bad spark plug, the issue can be solved with its replacement. If the replacement doesn’t work, you would have to check other fixes if the car won’t start when hot.
Fuel Pump Issues
When a car is running, especially in hot weather or under heavy load, various components in the engine compartment heat up. This includes the fuel pump, located inside the fuel tank. When the fuel pump gets heated, it will affect the motor. Furthermore, this will cause fuel pressure loss.
The car won’t start when hot due to the fuel system issues. Moreover, it can happen due to a bad fuel pressure regulator.
For that reason, the fix for these symptoms of a bad fuel pump is to conduct preventive maintenance. Also, change the fuel filters on time.
Vapour Lock
Vapour lock mostly occurs in older car models. While the newer models have fuel injectors, old cars faced a vapour lock. In this case, the liquid turns into gas and vapour bubbles. Besides, it blocks the fuel lines, causing the fuel system to fail.
One of the fixes if the car won’t start when hot is to give proper ventilation to the vehicle. Once the car cools down, the vapour will turn into liquid fuel and the car will start. Note that it is one of the main causes of hard starting when the engine is hot.
Bad Fuel Injectors
In a direct fuel injection system, a vapour lock isn’t common. A fuel injector sprays the fuel at the pressure in the cylinders. However, a bad fuel injector won’t be of the same use.
A symptom of a bad fuel injector is that it would cause a car to stall or not start. Moreover, when the fuel doesn’t reach the cylinders with pressure, it causes problems starting the car, especially when it is warm. The fix for this issue is to either use a fuel injector cleaner or replace the worn-out injectors.
Coolant Temperature Sensor
Due to varying temperatures, an engine coolant temperature sensor may fail. This can cause severe problems, such as the car won’t start when hot. A common sign of a bad coolant temperature sensor is the black smoke coming out of the exhaust. Moreover, it can cause the engine to overheat.
FAQs
What causes a hot start issue in cars?
Cars may face issues due to overheating. Here are some of the reasons why your car won’t start in the summer:
- Air intake issues or insufficient air supply causes the engine to overheat and not form a proper air-fuel mixture.
- Vapour bubbles block the fuel line and the car won’t start when hot due to this issue.
- Other problems may include car batteries, solenoids, spark plugs, fuel injectors and fuel pump issues.
Why is my car weak to start when the engine is hot?
The internal system, windings, solenoids and battery can be damaged due to extreme heat. This can also be a reason why a car starts for a second and then dies.
Why does my car struggle to start but run fine?
Sometimes a car takes longer to start due to the fuel pump issues. Moreover, corroded battery terminals can cause the car to struggle when starting.
These are all the reasons why your car won’t start when hot or it may struggle and take longer. When you buy a used car in the UAE or run an older vehicle model, you must take the car to a professional mechanic. Moreover, you can opt for dubizzle Cars inspection services to avoid future problems.
Stay tuned to the dubizzle cars blog and keep reading about the car issues that may arise over time and their fixes.
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