i just put in a new motor in my car and when it idles it jumps from 1500 to 2000 rpm i have asked acouple of people what they think it is and they have said a vacuum line has a leak if any one know how to check the lines or think of something else it might be pm me. thanks

 

Make sure the Evaporator Purge Valve and the Idle Air Control (IAC) valve plugs are not switched around. They are the same style plug both have two wires. Both valves are located on the back of the intake manifold. The IAC is close to the throttle body. The EPV is the little black plastic sensor held on by a screw to the far right of the manifold. It has a black circle shaped filter on the top of it.