I'm swapping a 2003 engine into a 1991 chassis with a Hydra ECU. The ECU instructions for wiring the coils bypasses the capacitor on the back of the cylinder head. I still have the 1991 capacitor in the harness, but it seems like it can only help to use the 03 one as well. I understand I need to tap the coils power wire and ground wire and run them to the capacitor (in parallel). Does the polarity matter?

 

This might be in the wrong forum. Anyone know if the ignition capacitor has polarity?

 

Capacitors always have polarity

 

FWIW, I removed that capacitor in my VVT swapped na6 chassis. But, I am also not using stock coils, and instead the D585 coils. I don't think that is of much help to you, but it is a data point.

 

Non-polar or bipolar capacitors are absolutely a thing. I don't know if that is the type used here.

 

That's what I've found through googling, but I'm the farthest thing from an expert

 

Ack, I was thinking of diodes. Mea culpa.