Still get the POP at high RPM

[FAST87]

Okay well I have the knock taken care of, but that damn pop is still there. When I nail it in first the boost shoots up to 17# instantly, and the car runs great. Right before it is about to shift into second or third, there will be that pop. The car will hesitate for a second when the pop sounds, and then it will go away and shift into second fine. The car runs perfect except right before it shifts gears. There is no knock so I don't know what it is. Maybe something is the coil???
Any ideas?
thanks

 

[Wes]

my buddies t type was doing something similar to that and he replaced the lower part of the coil pack and it took care of the problem