First try to do the combo without plinking as you seemingly do not understand the concept of links, chains and cancels. This way it is impossible for you to get out a lk or lp without physically pressing the button.
I’ll elaborate on your problem at the end.
Step by step:
cr.lk, cr.lp, cr.mp xx fireball
*cr.lk, cr.lp is a chain, this means one normal attack chains into another before the move is completely done.
Chains hardly require any timing, you can almost mash it and it will still combo. Only light attacks chain in this game and not every light attacks chains into one another, it depens on the character.
*cr.lp, cr.mp is a link, you have to wait before the cr.lp is completely done, this requires timing and practice. You will know the timing by experimenting, some hints to get the timing down:
-If the cr.mp doesn’t come out after the cr.lp then you are too fast, you have to do it slower.
- if the cr.mp comes out but doesn’t combo, you are too slow and have to do it faster.
A tip is to set the training dummy on “auto block”, it will block any moves that aren’t a true combo.
*cr.mp xx fireball is a cancel, this means you wil cancel the recovery frames moves of an attack into another. It is basically a chain but with special attacks.
A cancel has to be done as fast as you can while still being comfortable with it. From cr.mp you simply perform a QCF(quarter circle forward)+punch
Now to plinking, a plink should look like this when you look at the input display(which you can activate in training mode), the example below you are plinking mp and lp.
You always press the “heavier” button 1 frame before the other. This is a correct plink:
This is too slow:
This is too fast:
Assuming you are doing the plink correctly, you are performing the plink too fast after cr.lk, cr.lp resulting in you doing a chain, which is a lp.
You have to do the proper plink slower after cr.lk,cr.lp.
I hope this was clear enough.