crank shft snsoir keeps going out on 2005 Kia Sedona

some times it turns on and some times it wont..i took it so they could rebuilt the motor and thats when i started having that problom were it does not start it wants to but it wont untill a few hours later

Asked by for the 2005 Kia Sedona
If the engine was rebuilt and it is only then the problem started I suspect some electrical connection is not secure or a bad electrical ground, but it is quite possible that the problem is totally coincidental and that it is the starter that is failing. You say it doesn't start, does it crank over at all? I f not the starter or ignition switch could be the issue. If it cranks over but does not start you need to determine if it a loss of spark, a loss of fuel that is causing the no start condition. It is hard to guess without being able to do some basic diagnostic tests, but should be easy for a mechanic to figure out if they can get the car in a failed condition .