I'm leaning towards the ETA as well as I believe the throttle potentiometer is in the ETA. When it "acts" up the car will idle perfectly. There is just no way to get the engine speed up beyond 1500 no matter how slowly I depress the throttle pedal. It really seems like the rest of the fuel system has no idea the throttle is opening and is basically dumping a bunch of air into the engine without additional gas to compensate.