Plinking on pad consistently help

Classic Fighting Games Ultra Street Fighter IV
1

I Have problems with plinking on pad. My main 2 problems are:

  1. I have problem with Plinking consistently, I can’t seem to figure out the timing.

  2. Sometimes when I attempt to plink HP with lets say MP, Most of the time I end up getting a MP instead of a HP. It seems that i’m plinking MP with HP instead of HP with MP.

Anyone who is willing to help would be mostly appreciated.

Also, I play on a ps3 pad if this is relevant.

Here is my setup:
LP = SQUARE
MP = R1
HP = TRIANGLE
LK = X
MK = R2
HK = CIRCLE
PPP = L1
KKK = L2