No power at higher RPM's when boosting
 

I just put a set of HKS 272 cams in and had it tuned for the cams. Here's my problem... at idle and just cruising around its fine. but when i start to get on the throttle and boost, its like my car is holding back. my RPM's go to about 4000 and stay there. if i give it more throttle, i can hear my turbo spooling and watch my boost gauge go up but my RPM's dont follow they just sit at about 4000 (if i dont boost and give it light throttle my RPM's will go all the way to redline). I did a boost leak test and found no leaks. It smells like it is running rich so i checked my plugs and they a pretty black. I checked my timing again and it is right on. Any ideas on what is mechanically wrong or is it all tune related? If you think it is tune related, can you please recommend a place to get my ecu tuned or someone who tunes evo's on an AWD dyno in Pennsylvania. Thanks for the help!!!

Nate from p.a is very good..it seems to be your tune maybe the fuelcut tables are set to low and your hitting fuel cut does the car Buck??also put in a fresh set of plugs and have them gapped for your needs.

So your rpm does not go beyond 4k ? At first I thought slipping clutch, but your tach would shoot up and then may come back down after it catches....But if you are max'd at 4K, then it is something else...

Re-read your post and it does sound like you are hitting a load cut....

I know my clutch isnt slipping. i went through that with my stock clutch and thats not what this feels like. as far as it bucking... it doesnt really do anything. it just doent accelerate. thats why i was kinda thinking i need to get it tuned again. I do have a new set of plugs i was ganna put in after i got it running right. but i will try to put them in and see what happens. Does Nate from pa have a shop? and what part of pa is he from?

This is one issue I havent heard of. If you are running to rich, it will cause power loss. Here is an issue I was having that might be of some help. My car was pretty much useless. My BOV would flutter bad at partial throttle which was weird because it should be closed when on the throttle. I could not build up boost, and the car was hella sluggish. Issues were a full tank of bad gas, the HFC ended up failing and was trying to push the guts through the exhaust, and a boost leak. The car was running extremely rich also. We gutted the cat, replaced the fuel, drove it around until fuel was at 100 percent, and fixed the boost leak. After that the car was perfect and got a great tune.

Are you running a HFC, and is it possible you have bad gas. Bad gas will do weird things to your car that can cause serious issues. I found out that Shell stations distributors had way to much water in the gas.