1. It is easiest to check the condition of the components of the power system on a car raised above the ground - use a winch / lift, or drive the car onto a flyover / viewing hole.
2. If the smell of gasoline appears in the car interior while driving or after a long parking in direct sunlight, a thorough inspection of all components of the power system should be carried out without delay.
3. Remove the fuel filler cap and check it for damage and corrosion. Along the entire perimeter of the sealing gasket there should be a continuous trace of its tight pressing to the tank neck. If any defects are found, replace the gasket.
4. Check the fuel tank and its filler neck for punctures, cracks or other damage. Pay special attention to inspecting the junction of the neck with the tank. Sometimes the rubber of the neck begins to leak fuel due to the loosening of the mounting clamps, or as a result of aging of the material. Assess the reliability of the tank mounting. Only those of the possible problems are listed here, the diagnosis and elimination of the causes of which lies within the qualifications of the average amateur mechanic.
Never attempt to repair the fuel tank yourself (except for replacing its rubber components) - contact of residual fuel vapors contained even in a thoroughly ventilated tank with a gas burner torch or any other source of open flame can cause them to detonate!
5. Carefully inspect all rubber hoses and metal tubes of the fuel lines coming from the gas tank. Check the condition of the tube/hose material and the tightness of all fittings. Also check the fuel lines leading to the fuel injection system. Make necessary repairs, replace defective components (see chapter Power and exhaust systems).
6. Evaporative Emission Control System Components Another Source of Gasoline Smell (EVAP) (see Section Check of a condition of components of system of catching of fuel evaporations).