The EHA controls the fuel mixture by regulating the pressure differential between the upper and lower chambers of the fuel distributor. For emission reasons, it also turns off the fuel supply entirely when you lift your foot off of the gas at say 2000 + rpm and above and coast down to approx 1200 rpm where it will turn the fuel supply back on (rpm numbers are approximate and were changed during production). It appears that the CPS was your initial problem and the defective EHA valve you installed trying to cure the initial problem became your second problem. Mark