hi i've got a 87 rx7/lt1 with a problem. i pop's thru the intake at high rpm's above 4500 and lower under load. i've checked everything and this is what i found opti-good no vacume leak, fuel pressure 30-42psi, compression good,plug wires-good,plugs are white like new. ecu will not sync with scanner. any suggestions????????/ thank's in advance