I was checking all the vac. tubing in my z and found a bad line from the carbon canister to distributer vac advance to what i think is a deccel valve on the bottom of the throttle body, replaced it all, and now the idle won't hold, ether 800RPM or it jumps to 1500RPM i know deccel keeps the revs up to 1500 after a long high RPM run and that along pisses me off. any ideas? also my cold start valve is malfunctioning. could that contribute to the problem? kind of makes me want to take the whole emmission system out no more bleeding EGR, BCCD ect. Thanks again. Stan.