'03 silverado starter or ignition switch problem
 

Lately, when i turn the key to start the engine, the key seems to hang up in the start position and at the same time the starter engages but cuts in and out. The truck may or may not start when this happens. If I try again, it usually starts right away. I have a friend with a Suburban with the same problem. Is this possibly a starter, ignition switch, fuel issue, or other? Appreciate your comments.