Combustion adjectives are listed in this post. Each word below can often be found in front of the noun combustion in the same sentence. This reference page can help answer the question what are some adjectives commonly used for describing COMBUSTION.
actual, complete, direct, efficient
external, fuel, hot, human
imperfect, incomplete, internal, ordinary
other, partial, perfect, proper
rapid, slow, spontaneous
Hope this word list had the adjective used with combustion you were looking for. Additional describing words / adjectives that describe / adjectives of various nouns can be found in the other pages on this website.