Probably each driver faced such an unpleasant situation when the car stalls on the run.
A sudden stop of the vehicle creates a traffic jam on the road, causes discontent of other drivers and may cause an accident.
To exclude the possibility of such an outcome, it is necessary to understand what the reason why a healthy car suddenly stalls while driving is?
Finding out what the problem is very simple, you just need to check the work of the most “responsible” parts …
Can a car stall because of the plugs, such a small, inconspicuous part? Spark plugs “enliven” the engine, putting it into action. And if the car starts up with interruptions, stalls on the move, misfire at idle – these are the first symptoms of problems with spark plugs.
You can check the health of plugs in three simple ways:
- Check for spark. Remove the wire from the spark plug and touch the cylinder block with the contact. The appearance of a spark and its quality speaks about the performance of the part. But you can check the spark plugs in another way, without pulling the plugs. To do this, you must alternately disconnect the wires from the spark plugs to the distributor. If the sound of the engine does not change, then you disconnected the non-working plug.
- Check by a multimeter. A multimeter allows you to detect the presence of a short circuit inside the plug. Connect the wires of the multimeter to the two ends of the spark plug (thread and inlet), and follow the spark between the contacts. It should pass at a distance of 0,15 inches.
- Check by a gun. This method allows you to check the serviceability of the spark plugs but is not absolutely reliable. After disconnecting the plug, insert it into the groove of the gun, lower the cap and pull the trigger. If the plug does not spark even in the gun, then it definitely has to be replaced.
The electronic control unit of the engine consists of transistors, resistors, and microcircuits. ECU controls the process of supplying fuel to the motor and very accurately doses the amount of injected mixture. If the car stalled, then it is logical to check the health of the electronic device, which is responsible for the smooth operation of the engine.
You can test the ECU for performance in the following ways:
- Make sure that during ignition there is a spark and fuel flows to the engine from the gas tank.
- If the pump pumps the fuel mixture, injects it into the engine, but there is no spark, then the case may be in the ignition coil. Replace the installed coil control switch with a new, working switch, and if everything works, the cause is eliminated.
- It may be the other way around, there is a spark, but the fuel does not get to the engine, then the reason is in the injector control transistor. Check if there is a contact between the output of the switch and the ECU.
- Another reason why the car stalls on the move is the breakdown of the hall sensor (or the crankshaft sensor). In this case, there will be no spark and no fuel injection. If the sensor is working in normal mode, but the engine goes to failure, then the cause of engine failure is in the ECU. Electronic device must be removed and taken to the service station.
Diagnosis of the fuel pump
The fuel pump delivers the fuel mixture from the tank to the engine. This process must be stable; otherwise, in the event of a fuel supply interruption, the engine starts to work with interruptions.
Checking the operation of the fuel pump is carried out by an external examination, pressure test or with a special tester. Let’s learn more about each method.
An external inspection of the fuel pump may indicate the wear of its parts and, as a result, fuel leakage. If you notice a crack, found a leak, or just smell gasoline, then it’s time to get your repair kit.
The pressure in the fuel system can be checked using a pressure gauge, which must be attached to the ramp, and the instrument panel can bring to the windshield. The gauge should show 300-380 kPa when idling. Having switched the gearbox to the third speed, look again at the dial, if the sensor keeps the same indicator, it means that the fuel pump is working properly.
Another reason why a car stalls on the move is a breakdown of the pump relay. Connect the tester (bulb) to the relay and turn on the ignition. If the light does not turn on, then the problem is in the fuel pump.
You can check the charge level in the battery with a multimeter or a load plug. The multimeter can measure voltage both when the engine is on and when it is off.
In the first case, start the engine and connect the multimeter sensors to it, in the other case connect the device to the battery that is not working.
The norm for the engine turned on is considered to be from 13.5 to 14.0 V, and for the turned off engine – 12.5-13.0 V. Values above or below the norm indicate an insufficient battery charge level. Five out of ten cases when the car stalls while driving, is happening because of a poorly charged battery.
Charge metering using a load plug is a more accurate way to check battery performance. The voltage measurement procedure should last exactly 5 seconds. Pay attention to the voltage level immediately at the start of measurement and at the end. The first indicator should be in the range of 12-13.0 V, at the end – above 10 V. A battery with a charge below 9 volts is considered faulty and needs to be replaced.
To simplify your life and extend the life of your battery, you can purchase battery maintainer. It will maintain the battery charge at the right level, and you can eliminate one of the causes of failure.
Search for causes in the generator
The generator is also responsible for the smooth operation of the engine, and if the car stalled on the move, and all the above parts of the mechanism are normal, then most likely the cause of engine malfunction lies precisely in it.
The generator closely interacts with the battery, so the first way to check its health is to compare the voltage level of the battery and the generator, they must be the same.
For a more in-depth diagnosis of the generator, it is necessary to check all its details in turn. Namely:
- brushes and slip rings (looking for irregularities, furrows, and cracks);
- diode bridge (measure the resistance and calculate the conductivity);
- voltage level regulator (necessary only in case of undercharging/overcharging of the battery);
- stator (winding resistance should not exceed 0.2 Ohms and between zero and winding, not more than 0.3 Ohms);
- rotor (check of field winding and insulation resistance).
Check the performance of all the above mechanisms responsible for the engine, not so difficult, and most importantly – even an amateur who does not have special knowledge and skills can handle it. But the repair of the defective parts is better to entrust the experts.