Justin Bieber -- Taquitos Muy Bueno Cuando Estoy Drogado

We don't know for sure if Justin Bieber was stoned Sunday ... who are we kidding, he dropped more than $240 on fast Mexican food -- of course he was.

Justin and crew rolled up to celebrity hotspot Pinches Tacos on the Sunset Strip in West Hollywood on his way to Coachella and dropped $185 on a South of the boarder feast, consisting of:

-- 13 steak tacos
-- 9 chicken tostadas
-- 8 chicken tacos
-- 3 taco plates
-- 1 steak burrito
-- 1 chicken burrito
-- 4 orders of chips and salsa
-- 10 bottles of water
-- 9 Mexican sodas

Justin waited in a Mercedes van while someone from his crew picked up the grub and left a $55 tip, on Justin's credit card.

Ese Pinches Bieber.