Cranks but won't start

[neepawa]

My 2001, 5.0, V8 Explorer will not start. This was an occasional problem that has become more frequent. It happened the first time, several months ago after we nearly ran it out of gas, I thought there may have been an airlock in the gas line. It started after sitting for 30 minutes.

It cranks fast, but does not fire up (no battery or starter issue, and there is gas in the tank). If it does start, it runs fine. I took it to Pep Boys to have the codes read, everything is clear.

The K&N air filter was clogged, I have cleaned it and changed the plugs. It seamed to help, but it is back to not starting.

Any thoughts on what the problem may be and how to troubleshoot it?

 

[Blee1099]

Can you hear your fuel pump priming when you turn the key to on position? You can check for fuel pressure by disonnecting the line off the fuel rail and connect it to a bottle and see if you get fuel when cranking. If you don't it could be a fuel pump/relay/etc issue or related to your PATS lock system.