So I ordered an rebuilt opti from a parts store because they offered a lifetime warranty on it, but when I got it, it was just the optical part, no cap and rotor. So now I need to order a cap and rotor and was wondering how to make sure you line the rotor up correctly on the optical part? Or is there only one way to put it on? I didn't want to have my new opti open, but doesn't look like I have a choice. Thanks guys.

 

Might be a good idea to take the part you got back, and order a complete unit from GM, or take a chance on Accel, MSD, Summit, etc. The rebuilt units have not proven to be very reliable.

One thing thats confusing - if you have the back 1/2 with the optical sensor, why do you have to open your "new Opti".... it's already open if it doesn't have a cap and rotor?

The rotor is held on by two very tiny Torx screws. They appear to be slightly off-center, to allow the rotor to be installed only one way. Do you have the correct Torx screwdriver?

 

the rotor has a plastic pin molded in it that allows it to go on one way only