Car won't start, Please Help!

My car won't start! It turns over and over, but won't start. It's been looked at many times and I've been told it is getting fuel. I brought it to the mechanic and they replaced the ignition chip or something (whatever it was it cost $140). The ignition itself has recently been replaced. The wires and spark plugs have all been changed (I'm told I'm getting a spark) and so has the distributer cap and fuel filter. Sometimes it starts and will be fine for a few days, but it always dies out again and won't start for days. This has been going on for months and has become a very expensive problem. Please, any ideas would be helpful.

Littlemiss

Is your car pretty modern??....when mine used to stall, I had no hope of re starting it....ended up being Pick up Coil (inside the Dizzy)....is your car computer ok??....no stored codes???

Knowing what kind of vehical you have would help alot. If it is a newer car (90 or newer) it could be many things including crank position sensor, mass air flow sensor, or just a lose cunection someware.