Heard in the documentary Bridegroom, a character saying she had to call 911 for an ambliance (rather than ambulance) a number of times during her son’s childhood. The substitution has been reported in child language, as part of a more general shift
C/jul/ > C/li/
(facilitating ease of production) also affecting, for instance, ridiculous (> ridiclious). And it’s moderately common in adult speech (as in Bridegroom), presumably as a holdover from the child form.