You really need to be familiar with how this system works, and a decently experienced mechanic to diagnose problems like this. You can't just run an air line to a vac port and test for boost leaks, without blocking the turbo inlet, and the intake manifold. At any given time, a cylinder may be on the exhaust/intake crossover, where both valves will be open allowing air to pass straight through the engine while it is off. I have had the most success with actually inspecting every inch of the charge plumbing from turbo to throttle body, and then test driving. After that, make sure all your small plumbing to the turbo, WG actuator, BOV, and solenoids is 100% correct, and in great shape. Lastly there is the Actuator linkage, make sure that is attached to the wastegate, with the pin in place, if you have an adjustable WG, it may need to be properly adjusted.
Last edited by DerrickA; 05-15-2019 at 04:53 PM.