How to Troubleshoot a Malfunctioning Acura RSX Fuel Tank Cap
Failure of the Acura RSX's fuel tank cap is quite rare, but it can happen. And when the fuel tank cap does fail, it can compromise the fuel inside the RSX's fuel tank and, in turn, the performance of its engine. The following are some of the common problems associated with the Acura RSX fuel tank cap and how to troubleshoot them.
Check engine light is on
A Check Engine light on the RSX dashboard is one of the main indications of a malfunctioning fuel tank cap, but there are also other reasons for the light to turn on. If you have a handheld OBD scanner, you can use this to determine whether the check engine light is caused by a bad fuel tank cap. Hook up the scanner to the engine computer and check the code on the display. If the code is P0440 it means that fuel vapor is escaping from the tank, which is a likely indication of a malfunctioning fuel tank cap.
Dirty, corroded caps
If you notice sticky, old fuel residue on the thread and other parts of the fuel tank cap, it means that the cap is severely dirty and needs to be cleaned. Over time, particulates from the gasoline (particularly those that are of poor quality) may start to accumulate in and around the fuel tank cap. If left to build up, this can cause the cap to deteriorate and leak. The cap can be washed with lacquer thinner in order to dissolve the residue, but if it has already hardened to the point that it cannot be removed, it is recommended to have the gasket replaced with a new on instead.
If the gasket of the fuel tank cap has hardened and brittle to the touch, it may mean the gasket has worn out and needs replacing. Over time the gasket will dry out and become less pliable, leading to brittleness and eventual deterioration. Applying lubricating grease on the gasket will moisturize it and temporarily restore its pliability, although replacement of the gasket itself is a more permanent option.