A car's ignition process goes through multiple steps and components before powering up the engine. With hundreds of mechanisms involved at each stage, detecting the root cause for a car that won't start can be difficult. Here are eight common reasons that may be causing the problem.
1. Bad Idle Air Control Valve
The Idle Air Control Valve is prone to all types of clogging and can keep your engine from starting. First, clean your Valve thoroughly and check if it solves the issue. Besides this, the Valve may have an electrical problem that must be repaired by a professional only.
2. Severe Vacuum Leak
In this case, a hole in the air intake system may be messing up the ratio of air and fuel in your car. Having a spot can make the intake system let in unneeded air, causing too much air for the level of fuel present at each instance, causing the car to run "lean."
3. Anti-Theft Alarm System Issue
The reason for a stalling car isn't always mechanical. Your anti-theft system may be interfering with the ignition system. The design needs to be unlocked with the remote ignition key. Not doing so before starting it manually can cause it to lock up the engine. You simply need to unlock your car with the remote keys first to troubleshoot this.
4. Dirty Or Faulty MAF Sensor
A car's MAF is responsible for reading the airflow at each instance and allowing the needed air into the intake system. Over time, it can become clogged or otherwise faulty and start misreading the levels of air present.
This can cause it to let in either too little or excessive air, throwing off the needed air-fuel ratio for proper ignition. It's best to have it cleaned professionally to prevent any further damage.
5. Fuel Pump Leak
The fuel pump plays a pivotal role in pumping up the fuel to different car parts. A leak in the fuel pump can cause it to draw in too much or too little fuel leading to problems in the ignition process. To check if you have this particular problem, look for an illuminated check engine light as it always lights up in such a case.
6. Fuel Injection Sensor Issue
Like the MAF sensor, the Fuel Injection sensor detects the pressure present at each instant and injects the fuel level needed accordingly.
When faulty, it loses the ability to measure the pressure present accurately and exerts too low or too high pressure for fuel injection.
This, in turn, throws off the air-fuel ratio and prevents good ignition. It's best to seek out expert assistance and not try anything on your own.
7. Bad Carburetor
The carburetor is responsible for most functions of internal combustion and guides the air-fuel ratio. When clogged or faulty, it fails to maintain the needed balance between air and fuel volume and prevents proper ignition.
It's important to note that the carburetor is only present in older cars, so you don't need to worry about this for newer generation cars.
8. Engine Control Unit Issue
ECU is the program controlling all the major and minor functions of a car and rarely malfunctions. While less common, some programming of the ECU may have run into an error, causing the vehicle to stall repeatedly. Because it is highly technical, it is best to have it reset or repaired by an expert.