The Finite Rate Chemistry model initial temperature depends on the temperature dependency of the reactions. If no sensible value is known, restarting from a converged run (with residual values of the order 10^-4) that used the EDM model can be useful.

In cases where the domain initially contains air, you should specify oxygen with a mass fraction of 0.232 and set each of the other species to Automatic.

For Temperature, you should specify a value that is as close to the correct value as you can determine. This value should typically be above 900 K, and 1200 K is recommended as a starting point. If the mixture fails to ignite, running to a converged solution first with the Eddy Dissipation model and then restarting with the Finite Rate Chemistry model may fix the problem.