HELP!!!! I am stuck at 12 psi. I have a 76 280z, with a 81zxt engine. I am running the stock ECU and wire harness. I have Volvo IC. When i turned up the boost to 15 lbs once in a while in second gear the car would shake and backfire out the intake. it will do this like 1 out of 3 times accelerating. My a/f guage goes all the way into the lean. But why only sometimes.. and the other gears i can hold it out fine. I also have a turbo xs rlf bov... could that be leaking?? I have 2 washers shiming it. What could it be?? any ideas??