have a 93 auto 400horsepower supra whas in great condition till two days ago was on highways stepped on it n felt a great deal of power loss,now car wont pass 3000 rpm while driving n boost does not build up goes up to 0 n doesnt pass it....car baugs and when i let go of the accelarator car sometimes shuts off....when on neutral the car doesnt pass 5000 rpm...i thought it can be the coil packs... any suggestions or cluse???????