I have a 1.9 motor and i put a turbo on it. the motor has diamond pistons and crowder rod its all build to hold over 20 lb of boost it has a MSD boxs, crank trigger, innercooler and a FAST computer. the motors has been tuned on a dyno and has been running great until now

the problem

when reving up the motor when it hits 5000 RPMS it drops the RPMS back down to about 3000 even when floored.. I replaced the crank trigger sencer and the TPS what esle could it be ??