Well ignition points is the minimum temperature at which a substance will continue to burn without additional application of external heat. Also called kindling point.
the ignition point of fuel or the flashpoint if that is what your asking can be found with many instruments i find that the grabner miniflash system is the most reliable,
basically though it depends...
Ignition points are found beneath the distributor cap. Sets have 1 or two pieces depending on the brand. It looks like a small record player arm without the turntable. As the distributor shaft turns...
It has a flash point of about -50° F (-65° C)(lowest temp ignitable). The ignition temperature is about 495° or autoignition which it can go off without external spark source.