Engine Stalls While Driving

If the engine stalls while driving, one cause of stalling is something called vapor lock. Vapor lock can occur if the engine gets abnormally hot. So, then maybe vapor lock is causing this vehicle to stall.

If the stalling only occur if the engine is abnormally hot, then the possible cause is a vapor lock, vapor lock is probably occurring. At this point, you're probably wondering what exactly is vapor lock? And... how does it cause stalling? Well, vapor lock is when gas boils before it gets into the engine. It is triggered by an extremely hot engine. When the gas boils, air bubbles will form (in the gas), causing the air/fuel mixture to be too lean. By "too lean", it means that there's too much air and not enough gasoline. Consequently, the engine stalls since it can't stay running on such a weak (i.e. lean) air/fuel mixture.

What to do?

When vapor lock strikes, the only thing you can do is wait for the engine to cool down. Incidentally, why is the engine got so hot? Was there a good reason for this? If not, more than likely this vehicle has a cooling system problem - please look into this.

If the stalling occur at engine normal temperature, the possible cause is a faulty fuel pressure regulator.

First off, an engine that stalls while driving is generally having a fuel problem... specifically, a lack of fuel. The car that is equipped with fuel injection engines has something called a "fuel pressure regulator". Its purpose is to maintain fuel pressure to each of the fuel injectors. Any problem with this device will result in a fuel-starved engine and, of course, a fuel-starved engine will stall.

What to do?

You will need to have a mechanic verify that the fuel pressure regulator is faulty. If this is indeed the case, have it replaced. In a situation like this, some mechanics may offer to replace several other items related to the above. For now, just stick with the replacement of the fuel pressure regulator. This should correct the problem. You can always return at another time for the other items the mechanic suggested.