I installed this as a direct replacement, keeping the stock FPCU wiring. After a day of butt dynoing, the car suddenly lost all power and stranded me in an intersection. I discovered that one of the 25 year old capacitors in the FPCU popped and needed to be replaced. A quick stop at radio shack and some nifty soldering and I was back in business. Other than that the stock wiring seems fine. The idea behind the FPCU is to draw fewer amps at idle and cruise to, I'm guessing here, extend the life of your fuel pump.