i have a 98 monte carlo with a 3.8l. i replaced the head gaskets and put a new upper intake on it and it seemed to fix my water problem. also has new plugs, wires, water pump, and starter. it idles at 1,000rpms and its doesnt run perfect. i checked all the vaccum lines and they are fine.the only thing that i seen that could cause this is that the canister is missing. looks like someone hit something and it ripped off the plastic peice underneath that the canister mounted on. Any tips? Thanks