I bought TGP1 too, And what a joy !!!!!!! its simply fantastic to drive GP2
with this one :-)
Use no steering help, but use lock-help, otherwise the car will spin to
easy !!!
And your problem !!!!
Experienced just the same. Try to clean the accelerator and brake pots with
some contact spray.
After half a day of hard track-work, clean them again. And then once more
!!!!!!!!
It worked for me, I hope it work for you !!
Mose