FORD F-250 IGNITION SWITCH KEY

Truck Will Start But Quits If I Go Over A Bump - If I Grab Key/ignition Switch, Fast Enough I Can Keep It From Quitting Until The Next Bump...

I Just Finished Installing A New Used Engine In My Truck Listed Above Power Stroke. When I Turn The Ignition Key To Start And Let Go It...

When I Turn The Key To Start The Vehicle Starts Right Up, As Soon As I Release The Key It Dies. I Have Kept It Running By Holding The Key...