Losing boost.. wastegate issue?

[Joshlc1988]

Hey guys, I'm new to the forum but I've been reading and learning a lot from these forums. I do all of my own work an diagnostics on my Audi but this one is really driving me crazy so I'm asking for help. My car is a 2006 a4 s line 2.0t with 124,000 miles. In February I got a jhm stage 1 tune, jhm hfc, and afe dry flow drop in. About 6 weeks ago I switch to r8 coils and colder ngk plugs, and also did the timing belt and water pump job. The car ran great for awhile but I've noticed power has started lacking. I do have vagcom and after logging the car I can see the lower actual boost and the fall to wastegate pressure in the high rpms. It had a steady 3.5psi drop from specified until right past 4000 rpms then dives to 10 or less. I adjusted the wastegate and I now get a good spike but it immediately falls back under. I just did another pressure test yesterday to 30psi and all is well. Can someone tell me if this seems normal or if my gate just isn't holding?

[Joshlc1988]

Every log is just like this... occasionally it will spike at specified but drop right after. I've also checked the timing tables an no timing is being pulled. Lambada is spot on, an maf readings look good. The thing that's getting me is the n75 duty cycle starts and stays at 94.9% through the entire pull. Only if I get it to Spike at specified will it drop the go right back up as soon as it goes under specified. Am I over thinking this? Is this normal?

[Joshlc1988]

Update: after rechecking my wastegate actuator I found that my spring is weak. So I tightened up the rod a bit more. So far so good! Boost spikes a bit above spec just over 20lbs and follows much closer to the specified graph until higher rpms. I can live with it until I go BT. I did discover a big dip where the boost spikes on my hphp log. After checking the lpfp logs I believe it's about to go. Duty cycle starts in the high 80s and pegs 94.9% until redline.