wierd boosting problem

[FD3SNuttah]

im sorry for making a thread but my mate howie has a really wierd boosting problem. i cant find answer by searching

on the weekend i went round to his and his rex isnt boosting properly. so did the usual check for leaks effort and found that he didnt have any boost pills in the actuator pipes. So replaced them and still no second boost

i went home then an hour later he phones me and then says that the car was boosting properly?!  seems to only boost properly after a long drive? anyone had something similar?

[Jono FD3]

Could be a laisy solonoid in the rats nest??

Jono