I have a 05 Wrangler Sport 4.0. A vacuum line fell off near the intake manifold that leads to the AC. Once it fell off my directional control knob on the dash stopped working about a year ago. I just recently noticed the disconected line and reconnected the line. The directional control now works but the Jeep now wants to surge when stopping and will continue surging once stopped. I have since re-disconnected the line. Please help.

vacuum lines are no hard to find
usually they com out of the intake manifold and go to the actuators
follow the small hoses

Vacuum supply starts on the drivers side of the engine. There is a vacuum line going into the brake vacuum assist from the manifold. branching off of that line is a double line that snakes under the intake manifold, behind the valve cover, along side the valve cover on the passenger side headed to the front of the engine. Then it curves to the right side of the engine. One set of hoses from this line goes to a valve control (red and green i think). The other line goes to the vacuum storage ball, it should be black. The vacuum circuit continues out of the ball in another black line that snakes into the firewall. It goes under the heater core black box and disappears under it. Now go into the passenger compartment and drop the glovebox. look to the back right you will see a black and a white vacuum line coming out of the firewall. The black line is your vacuum supply from the engine. It goes up to a little rubber manifold. disconnect the lines coming from the dash switch and check for vacuum on the manifold where the black line is going in. The white line controls the cabin air intake under the glovebox and the thermostat shutoff under the hood. It should only have vacuum when the switch is in a certian position, AC probly. The other three lines coming off the rubber manifold snake behind the dash vent door assemble and come out near the gas peddle. The red one controls the dash vent. apply vacuum to the red hose and see if the vents go to the center dash position/AC. The yellow and blue? ones control the floor vent control near the gas peddle. yellow gives you half floor and half defrost. blue gives you all floor. you can use a small vacuum line to connect the black vacuum supply to each individual line on the manifold and check the function of each vacuum control assembly individually. I hope this helps. On my truck each control unit works fine when i apply vacuum to them individually but when I hook the dash switch up to the rubber manifold it goes to defrost. I tried changing the dash switch and the lines running from the switch to the rubber manifold and the vacuum ball under the hood, nothing works. I suspect I may have leak i just haven't found yet. next step is to get a vacuum gage and start checking the amount of vacuum i am getting at each vacuum line. I'm sure it is supposed to be getting a specific amount of vacuum and will not work if the vacuum drops below a certian level due to a leak in a line somewhere? God bless.

You may have a vacuum leak. The leak may be at the intake manifold (upper or lower) or any of the vacuum lines leading to the various sensors or the brake booster (larger hose leading from the upper intake to the large round device behind the master cylinder near the firewall on the drivers side). You should find (usually) a vacuum line diagram affixed to the underside of the hood near the front, or on the framing near the radiator. Also listen for a tell-tale hissing when the engine is running this may help you locate the leak. Hope this helps you.

Intake runners are controlled by vacuum actuators at the rear of the intake manifold (I think it takes a 8mm socket--two bolts for each actuator). First check them both for loose of bad vacuum hoses. You can remove the actuators and see it the runners are free to rotate--perhaps one is corroded and stuck. You can take the air horn off the intake manifold, if necessary, to free the runner; but you may need to buy a new gasket to reinstall. Let us know if you have more questions.

The air control doors on your vehicle are vacuum operated and shift by themselves to a "default" position [which is defrost] if the vacuum is lost. I would suspect that you have a broken or leaky vacuum supply line near the engine somewhere which is preventing vacuum from ever reaching the control panel. Look for a broken or leaking small 1/8" or so diameter black plastic vacuum line near the rear of the intake manifold area on the engine. This line may go to a plastic vacuum reservoir or it might just go right to the firewall and pass through it with a group of other items [it varies from model to model] If you can't find it you might need to have someone at a service facility track it down for you. Should be a fairly simple fix. Good luck, hope this helps a bit!

Probably a vacuum line. Most heater controls are ran by vacuum and their is one vacuum line that goes from the troddle body to the firewall on the passenger side of the car. Check for a broken hose.

Look for a vacuum line passenger side rear under hood near hood hinge area. Follow this line back to the intake manifold. checking for crack and leaks if any breaks in this line repair them this should fix your problem if not check all vacuum lines under the dash as well as the vacuum diaphrams that control heater door operations. if you have a hand vacuum pump you can check all these at (previous found) intake connection for the heat controls

thottle position sensor out of adjustment or bad

Check all vacuum hoses for leaks, check cap rotor wires and coil for arcing.

vacuum originates at manifold but goes to a storage tank and is sent to axle through a switch control.