1992 G20 sport can conversion idle issues

My van when in neutral or park would idle high but drop to normal when In gear. 2 weeks ago I went to start and would not fire. Checked everything all looked good. Came back the next day and it fired up right away however the rpm's shot through the roof absolutely red lining the rpm's. Shut it down I knew I had an idle air control sensor issue so I went out bought a new one. Installed it but when taking out the old I disconnected the map sensor vacuum line from the sensor to get room. Started up idle was fine but ran rough as hell realized vacuum line was still off reconnected the line and rpm's skyrocketed again. Replaced the map sensor hooked up electrical reg idle hooked up vacuum boom rpm's skyrocket. I've pulled the line it's clear and not collapsing I snapped the coolant temp sensor top on accident replaced that. I'm at my wits end about to tow to the junkyard but I love this van and its got a great engine just can't figure out why it's revving sky hi every time I hook up the map sensor vacuum line. I've checked ever line and hose their in good shape. Please help