Is dahlia ˈdeɪljə an exact rhyme with failure ˈfeɪljə? Well, yes and no. The possible difference between them is not a matter of i̯ as against j, but rather of our awareness of the varisyllabicity in dahlia as against its absence in failure. We know that dahlia can optionally be said with three syllables (by some of us, at least), while failure can only have two.
Source: wiktionary