Why Does My Car Stall At Idle? Causes & Fixes
Does your automobile stall when a traffic light unexpectedly turns green? Everyone understands how frustrating and embarrassing this can be. Putting aside the worry and shame, if your car stalls at idle, it could suggest a more serious problem.
Typically, this is due to a lack of fuel, power, or air entering your engine. However, like with many car-related issues, the nuances and complexities of engine stalling necessitate a thorough grasp.
Fortunately, this guide will uncover the exact causes of your automobile stalling at idle and offer efficient fixes. Let’s investigate and clarify this subject for a better understanding!
Some Common Problems Leading To Car Stall At Idle
Air Delivery Problems
[1] Throttle body problems
A dirty or clogged mechanical throttle body can reduce airflow, causing the automatic car stalling at idle. Vehicles made after the mid-2000s have an electronic throttle body controlled by the vehicle’s computer. A problem with either the electronic throttle body or its wiring can cause the engine to stall.
Solution: Cleaning in a general auto repair shop should fix the mechanical throttle body problem. For an electronic throttle body, circuitry should be checked, and if the circuitry is okay but the problem persists, a new throttle body or actuator will be required.
[2] Idle air control valve problems
The idle air control, or IAC, valve governs the idle speed of an engine by controlling the flow of air around the throttle plate. If your dashboard comes with a tachometer, you can see for yourself how the IAC valve works.
Engaging the air conditioning can advance the idle speed from 700 RPM to 1,000 RPM to allow the engine to take a better load. This means your IAC valve is doing its part to prevent stalling. A dirty or malfunctioning IAC valve will cause your engine to starve for air, which is the reason why the engine stalls at idle.
Solution: Typically, cleaning the IAC valve passages within the throttle body resolves the problem of why my car stall at idle. If your vehicle operates well at cruising and highway speeds but experiences poor idling and eventual stalling, this should be your first place to look. Most IAC valves are located in the throttle body.
Fuel Delivery Problems
Several reasons usually cause poor fuel pressure, but the most common one is the fuel pump, which is one of the reasons my car is not starting. This can cause the engine to lack fuel, which will stall it. Other causes of poor fuel pressure are a clogged fuel filter or fuel line and a faulty fuel pressure regulator. In general, faulty fuel injectors or two are usually enough to cause the engine to misfire but will not stall it.
Solution: Given the dangers associated with gasoline, it is best left to a professional for general car repair. If there is low fuel pressure, you will generally need a new fuel pump.
Also Read: Tips to Avoid Fuel Injector Cleaning Mistakes
Sensor Issues
Two primary engine fuel management systems are being used currently, which are speed density and mass airflow.
In a speed density system, the vehicle’s computer controls the fuel injector using information from the TPS, MAP sensor, CTS, and IAT. A malfunction of any of these sensors or circuits can cause a car starting problem.
In a mass air flow system, the computer modulates fuel injector control based on data from the mass air flow (MAF) sensor. An issue with the MAF sensor or its circuit can cause the car to stall or not start. These are common sensor-related reasons why your car won’t start. However, other sensors might cause similar problems.
Note that all sensors report information to the computer. A sensor does not act but reports. If the computer determines that sensor data needs to be changed, it uses an actuator such as the IAC valve or fuel injector to make the change.
Fortunately, most sensor faults will illuminate the check engine light and record a diagnostic trouble code, which can help guide you in diagnosing the problem.
Solution: If you have an OBD-II code scanner, you may be able to find the bad sensor. A professional mobile mechanic Perth should do most repairs, however.
Ignition Problems
Almost all vehicles manufactured within the last ten years rely on a coil-on-plug ignition system. In this system, a high-voltage ignition coil is mounted above the spark plug and fires the plug when it receives signal voltage from the ignition timing device or computer.
It manages the timing of the ignition on this vehicle’s computer based on data it receives from three sensors: the crankshaft position sensor, camshaft position sensor, and knock sensor. A failure in one coil or plug will not necessarily cause stalling. The engine stalls if its crankshaft or camshaft position sensor or ignition switch fails.
Solution: Identify the source of the ignition problem. Often, the repair is a matter of replacing the crankshaft or camshaft position sensor or ignition switch. These tests are best left to your general mechanic Perth.
Vacuum Leaks
A vacuum leak allows unwanted air to get into the engine. This causes the engine to run lean, which means it is getting too much air and not enough fuel. In extreme cases, if the leak is quite severe, it can result in car engine stalling, though most leaks are minor and have different symptoms. The common causes of vacuum leaks include hoses and lines, PCV valves, and intake manifolds.
Solution: A car mechanic Perth can detect and correct the source of the vacuum leak.
Charging System Problems
[1] Battery problems
A failing battery or loose/damaged cables can cause the car to stall at idle suddenly.
Solution: Battery cables may only need tightening, or they may need to be replaced. If the battery is bad, it should be replaced, or it might lead to the car engine stalling. Most people can handle such problems, but they do need to exercise caution against electrical shock.
[2] Faulty Alternator
The alternator recharges the battery and drives the vehicle when the engine is running. A faulty overcharging alternator can affect the vehicle’s electronics, or a low-charging alternator may prevent battery recharging and impact voltage for onboard electronics, both of which are the prominent car not starting reasons.
Solution: A defective alternator needs to be replaced. This repair entails significant disassembly and should not be done by an individual.
Engine Problems
An engine with low compression might not generate sufficient power to continue functioning. The engine may shut off immediately after starting or when subjected to a load.
Solution: Generally, the engine will require rebuilding or replacement. This repair can be costly and may not be justified based on the age and value of your vehicle. Consult with a best car service Perth based service centre, calculate the costs, and determine if purchasing a new car would be more advantageous.
Conclusion
Many people compare vehicle ownership to elephant ownership since both require maintenance, whether they are in use or not. While this analogy has some validity, an elephant does not provide air conditioning or music while travelling.
Therefore, it is necessary to know why your car stalls at idle and seek appropriate solutions instead of whining about ‘my car is not starting’. Utilize the information provided by the team of expert technicians at Auto Service Perth, to improve your car repair and maintenance and prevent such issues from happening again.