Why does my car fail to start?

Thursday January 16 2020


By Paul Kaganzi

Hello Paul, I have a Toyota Premio with a petrol D4 engine which stops running after warming up and will not start again. However, when the engine cools down it starts with one kick. Why? Mugisha

Hello Mugisha, your Toyota Corona with a Direct 4 petrol engine seems to have a problem with one of the engine management system components or sensors. Your Toyota and those built after the 1990s have petrol engines whose fuel and spark delivery is controlled by an engine control module (ECM).

This computer is regulated by different sensors on the engine which enable it to adapt to the different driving demands such as uphill driving, cold starting, warm starting and acceleration, among others.

Very often when the engine management system fails, the “check engine” light is displayed on your dashboard. You, therefore, need a computer diagnosis to point out the faulty component. In your case, subject to a diagnosis, the likely faulty part is the crank angle sensor (CKP) which reads the engine speed via the flywheel.

The CKP works with other sensors such as the camshaft position, oxygen sensor and mass airflow sensor to regulate the ECM. The crank shaft position sensor which uses magnetic (Hall Effect) to read the flywheel speed will not work properly if its magnetism has deteriorated, especially as the engine warms up. Find a Toyota garage with a diagnostic computer to confirm the fault.