This document provides troubleshooting tips for common vehicle engine issues. It lists problems such as loose electrical connections, insufficient fuel, vacuum leaks, and malfunctioning engine control systems that can cause the engine to start but immediately stop. Other issues covered include an empty fuel tank, low or discharged batteries, faulty ignition components, and problems with the fuel system that can cause the engine to rotate but not start. Tips are also given for issues that can make the engine hard to start when cold, such as a discharged battery, malfunctioning fuel system, or leaking fuel injectors. Remedies include fixing electrical connections, cleaning or replacing various components, and checking diagnostic trouble codes.