i need help wiring my si to an 90 ls. i bought the car with a zc in it already so i pulled it out and im thinking about wiring it back to an si again an then starting all over again becuz the wires are a mess. i need to know what wires at the ecu plug need to be switch around/or added and what wires need to be switch around or added in the engine bay as well. any wiring info on this swap would be great
thanx in advance

 

all you need is a stock si wiring harness no the engine and fi you are using a 90-91 motor the ecu should plug in....if the wiring is messed up just buy all stock si parts...

 

ya what you need to do is return it all to stock.....any wires that were spliced at the ecu should be put back to stock, and buy a new si wiring harness for the motor.....the ls swap is the easyiest b series, its totally plug and play......gl

 

88 Si with ZC would not require any changes to wiring at the ECU - only changes would be at the distributor - if it was a DOHC ZC, the connector at the distributor should have been swapped from the round 7 wire connector to the square 5 wire and should have 2 wires (blue/green and blue/yellow) extended to the Cylinder Position Sensor on the end of the exhaust camshaft - that is only wiring changes required on the Si harness