Justin Bieber -- Taquitos Muy Bueno Quando Estoy Drogado

EXCLUSIVE

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.