i'm having this problem sometimes when i start my car.
it sometimes feel like it won't turn on, i have to hold on to the key for alittle longer then normal, and sometimes give it alittle gas to start it going.
when this happens and i let go of the key the car is at 500 rpm. and the car shakes for awhile, like it is struggling or something.
my battery is new, what can it be?

 

My guess is your ignishion coil is going out...or is out..this is under the distributer cap.

 

Try replacing your distributor cap and rotor first and see how that does, extremely simple to do.

 

low on gas?

 

mine does this occasionally, sorry don't have any answers though, i noticed it is more frequent when low on gas though, or parked up hill or downhill, but may just be coincidence.