Hey you Pikachu uses Boot Cic 6102, South Park Rally Pal uses 7101 (which are the same), so this should definitly work.
Did you tried to boot up South Park Rally on your Pal console in order to see if the game works fine?
I had a similar problem with zelda ocarina of time Jap. It worked fine after I cleaned the contacts with a Q-Tip and some water.
Maybe you have the same problem with one of those games. Clean both of them and it should work (also try to clean the import adapter).
If this is not working, there is maybe a configuration problem with the blaze adapter. I don't have one, but I had once an Xlpoder (also from blaze). In order to boot up some games, you had to use different boot codes (push the button on the right).
As it looks right now, I would go for an Everdrive 64. It is basically an N64 Cartridge where you can Load Nintendo 64 Roms from any Region and play them on a Pal System. There is no more Region Lock problems etc.