I am hanging out at the beach for the week so I don't have all my stuff to research this. With that being said, can someone tell me what exactly does the factory S4 ECU control? I know it controls fuel, spark, and air flow....anything else like gauges, any of the power accesories, lighting, etc. ??? Please advise.

 

Fuel, timing, emissions, etc...take a look at the pin outs in the FSM & the wiring diagrams. I believe the boost gauge gets its Ref voltage from the ECU, but it's not controlled by it. Some of the other gauges act independently, but the tach definitely needs the ECU to be plugged in for its signal as well.

And the ECU doesn't have anything to do with accessories or lighting.

 

That's pretty much what I was thinking but couldn't confirm without having my stuff. If I am switching to a distributor ignition then I guess I could eliminate the ECU. Sound right?

 

Distributor and a carb, can't control the FI without the ECU.

 

Thanks Banzai, just trying to keep it quiet about going carb, but that is already in the plans.

Carb + distributor = removal of ECU? Correct?