I have a 2005 Jeep Wrangler X six cylinder, just started to have some trouble with it today. The Vacuum line that controls the heater switch for defrot and heat fell off the conections near the manifold. re-connected it and now the engine surges when you come to a stop and in drive wants to lurch vechile forward. Put in park surge goes away. Disconnect vacuum line from drivers side engine (by manifold) goes away also. any clues to what is causing this? Could it be TPS?