Previous research on phonological priming in a Lexical Decision Task (LDT) has demonstrated that second language (L2) learners do not show inhibition typical for native (L1) speakers that results from lexical competition, but rather a reversed effect – facilitation (Gor, Cook, & Jackson, 2010). The present study investigates the source of the reversed priming effect and addresses two possible causes: a deficit in lexical representations and a processing constraint. Twenty-three advanced learners of Russian participated in two experiments. The monolingual Russian LDT task with priming addressed the processing constraint by manipulating the interstimulus interval (ISI, 350 ms and 500 ms). The translation task evaluated the robustness of lexical representations at both the phonolexical level (whole-word phonological representation) and the level of form-to-meaning mapping, thereby addressing the lexical deficit. L2 learners did not benefit from an increased ISI, indicating lack of support for the processing constraint. However, the study, found evidence for the representational deficit: when L2 familiarity with the words is controlled and L2 representations are robust, L2 learners demonstrate native-like processing accompanied by inhibition; however, when the words have fragmented (or fuzzy) representations, L2 lexical access is unfaithful and is accompanied by reduced lexical competition leading to facilitation effects.