Boost in 1st
 

I know this problem has been talked about over and over for stock twins but I'm not sure if my problem is a little different. I'm still on stock sequential twins, with full 3" exhaust and no air pump HKS RS intakes and HKS v-mount. Apexi PFC computer using the stock boost control. I am not getting the boost creep problem at all with this setup and am getting the perfect 9/7/9 (or whatever it is it's been a while since i looked) transition in every gear except first. If i go full throttle in first i am pulling vacuum by 6k unless i only give around half to 3/4 throttle and then it will actually boost. I've checked all couplers and have no boost leaks and am a day away from tearing into it and changing the typical solenoid that people say causes this problem, if anyone else has seen this am I going to waste my time? TIA