Hi all. I've got an intermittent boost problem, when I floor it the gauge will go above 3/4 On the gauge and it pulls like a train but sometimes it will only go to just under 3/4 and not pull aswell? Cars got standard injectors and turbo but has been mapped and had an aftermarket boost control valve mounted to the bulkhead. Cheers

 

Check all the hoses, could be something as simple as a boost leak