I have a 1998 F-150, standard trans, 4.2L. The other day, the starter failed to engage. I can hear the solenoid on the firewall clicking, but the started isn't activated. If I bump start the truck, then shut it off and try the key again, it works. If I leave the truck be for an extended period (by this I mean 2 hours to overnight) and try again, same thing...only solenoid clicking. I tried to swap out solenoid on firewall, no luck. I think it may have something to do with the key/ignition. The starter is newer, and obviously works because like I said, it will fire if turned off, then immediately started again. Any comments?

 

sounds like the starter is bad...... the next time it wont start... tap on the starter with a hammer... if it starts up after that i would change the starter

 

check your grounds and all other connections.