I've got a 1996 f-150 with the 5.8 engine. I've been having trouble with it cranking lately. Sometimes it'll just sit there and turn the engine like everything is ok but never crank. Other times it'll crank right up. It's not the fuel pump. What could cause it to turn over like that without cranking? Thanks

 

you mean what would cause it to turn over and not start/fire? cranking and turning over are the same thing in my opinion.

Have you pulled codes? that year would be OBD-II and any auto parts store would/should pull codes for free.

 

Unplug the TPS and crank, see if it works. If no difference, try unplugging the IAC to see if it cranks. I can't remember which one was causing my problem when I first got my truck a few years ago, but I replaced the part causing the problem and it's been perfect since.

But otherwise, like Kemical said, pulling the codes is the best way to go.