Well, after transforming the Williams, I have a problem that I tried fixing now for a while.

I changed the engine for an younger one with less miles on it and K-Tec head, Piper cams and adjustable pulleys. Since this, when I try to put the throttle down, it feels like running into fuel-cut...
I checked the cam setting, the Sparks, the wires, the injectors, the TPS, the throttle body, the Ecu, and the fuel Pressure regulator and nothing seems wrong. The car drives OK when you rev it slowly, but if you step on the gas, it does not work.

Anyone got an idea that did not come to my mind?