I have a 2008 Tiburon GT, was driving very good, I took the car to the mechanic to change the lower arms he did it but now when about to start the car sometime does and some time does not, when it does not I have to give him a jump, it has a brand new battery, alternator is charging, I believe was the starter but now I think is something else, can the ignition key cause that problem? any help will be appreciate.
Thank you.

 

If it starts every time when you jump the battery ,I would look at the connections where the cables attach to the battery.
All you are doing when jump starting it is; adding addl power to the vehicle.which is not getting there from the vehicle's battery.

There are times when a poor connection at the starter will produce the same symptoms.