BTW the tach is very erratic bounces everywhere, what sensor sends the signal for the tach?

if the ECU is bad, should there be any visible signs or smells. becuase i check the ecu and opened it up all the connectors look good and the inside looks mint, this ecu has been changed before i think it is from a 93 eagle talon TSI as thats whats stated on it.(has the markings form a salvage yard.

if anybody would let me plug my ecu into their car that would be great