flat spot
 

hi guys,
on my00 uk turbo,
when i go to put my foot down i get a flat spot at 3500rpm sort of holds back then goes,i can hear the tubo spooling up and wants to go but it likes it got a flat spot

i cleaned the boot solenoid with brake cleaner,

any ohter ideas?

other bits to clean if so the location would be a help;)


big thanks for anyone who helps