Hi,
I think you just should press the right button at the right moment
You can try to press them some ms quicker...
I'm sure you will solve it.
Just try to press a little bit quicker than you do it now...
(That was the problem for me...)
I don't know how I can help you more...
Good luck!
P.S. It is some years ago, when I played GTA: SA
Greets