At times my 2001 f150 cranks but wont start. Can keep trying but just keep cranking. But if i turn switch off and then back on and try it starts on first try.It has done this multiple times. Does anyone have an idea what to check?

 

The ignition switch powers up a lot of circuits.
It could be the ignition switch, the PCM relay or PATS.
The two major systems that need to be powered are the PATS and the computer.
A failure in any one of these three areas is a no start even though the starter circuit cranks the engine.
On the engine proper, if the front crank sensor plugup was intermittent there will be a no start as well.
Good luck.

 

Thank you for the info. Will try to track it down.

 

My 2000 does the same thing..I had a fuel pump failure,and the symptoms then were identical...replaced the pump assembly and still have an occasional no start/stall/stumble...Haven't narrowed it down yet....

 

About to post about the same type issue and what my dealership said.

 

Go read your updated thread.