I have a 2003 Liberty 2.4L with about 180k miles on it. I recently started experiencing rough starting, having to crank the engine over for extended periods of time before it would catch. I replaced the spark plugs and installed a new ignition coil. That didn't seem to solve the problem. I then replaced the crankshaft position sensor. Now, it wants to stall out if no gas is applied on startup. If I get it running, it will idle around 1000/1500 rpm, but then if I accelerate and let off the gas, it will die again. No check engine lights come on. Reading some other threads, maybe it's the Intake Air Control? Camshaft position sensor? Do those go bad and NOT have a code?