Engine cranks but only starts when it wants to

Hello,

I have a 1999 5spd kia sportage. I have had this problem for probably over a year and a half now. The car was bought brand new and worked fine. But my problem is the engine cranks when trying to be started but sometimes doesnt start, but if i move the shifter back and forward for a while the car starts. I have taken the car to the shop and they say its fine, i have checked every problem and even installed a push button start and the problem still occurs. Can anyone help me?

As I understand, the starter cranks every time..but the engine does not fire up. Then , apart from freak problems, (I think the shifter is a coincidence) idle air control (IAC) valve and crank position sensors are to be investigated.
IAC needs to be cleaned..almost a normal maintenance item. www.geocities.com/lmp4203/kiasport/IAC.jpg remove and clean with gas or carb solvent.
If this does not correct the problem, crank position sensor has been reported a culprit several times. www.geocities.com/lmp4203/kiasport/cam_crank_sensors.jpg (hard to get...need to go under) ..and this is common to all makes of cars.

Thanks. i'll try that