Boost Problems

[NC Firefighter]

I put an he351 on my truck about 2 weeks ago and I'm having trouble with it. It ran good when first put on. I built a spring wastegate and set it at 40 psi and it pulled like a champ, considering its still mostly stock. But a couple days ago I got on it a little and boost went to about 35 and started dropping. I let off the throttle and when I got back on it it wouldn't spool. I figured a leaking boot or something but everything was still normal. I pressurized the system and didn't find any leaks. Drove it again and it now spools like normal up to about 20 psi, but won't go any higher. I can get it to spike to about 30 if I try but it just falls right back to 20. I've checked for leakes again but found nothing wrong and I'm kinda stumped. Sorry for the long post, I just wanted to be as descriptive as possible. I've searched and can't find anything that sounds like what I have. Any help would be greatly appreciated.

 

[SethR]

Is it still fueling hard? Do you still have the sensor in the comp housing?

 

[NC Firefighter]

Sensor is gone and hole completely sealed, all three of the holes are filled so no leaks there. I think its still fueling like normal, but with the low boost I won't be getting full fuel anyway right? With the HX35 that was on it I had the wastegate set at 35 add full fuel around 25 to 30. I sett it to 30 on shop air but I still had to play with it some once on the truck.