I've got a 2003 F150 5.4L XLT that's cranking, but not starting that I could use some help troubleshooting.

When it first started happening my girlfriend had tried to get in with her (factory) key on the driver's side. That lock isn't working with the key, but does open and close with the keyless entry. She was able to get in on the passenger side with the key and get what she needed out of the truck. When I got back from out of town it wouldn't start. It was flashing the "theft" light on the dash quickly. A tip I got somewhere online was to unhook the battery to reset the antitheft system - did that for 15 minutes and then later for 3 days, nothing. The theft light is now off though, no blinking. When it sits for a day it cranks and feels like it is almost going to start the first time I turn the key. After that it just cranks.

Any ideas on what to try next? It's got a full tank of gas for what it's worth.

 

Yeah, that pretty much never works...

Verify that PATS proves out correctly: 1) Slow-flashes while truck is OFF, 2) When key is turned from OFF to RUN/START, should come on for up to several seconds then go out.

Does the fuel pump cycle on for several seconds when the key is turned from OFF to RUN (not START)? Listen carefully, put your ear to the opened fuel filler, if needed.

What does the check engine light do when 1) the key is turned from OFF to RUN (not START) and 2) turned all the way to START? Does the tach, if equipped, register while cranking?

 

People often only notice the PATS light when there are problems.

 

Ford's description of what happens if you try to use the wrong key is not really clear. "May lead"? "no-start"? Vague. Makes you think you should throw away any uncoded keys. Too dangerous.

 

I appreciate the response and help. I've been away from the truck, so haven't been able to test these out.... to answer your questions:

1.YES. Truck is off and the theft light is flashing briefly every second or so.
2.YEP. Stays lit for about 3 seconds and then goes off

Possibly. There isn't a continual noise, but when I turn key to RUN position there is a sound about 1.5 seconds later when I have my ear to the fuel filler that sounds like as a slight metal rubbing.

1. Battery, Parking brake, Seatbelt, Service Engine Soon, Oil Pressure lights turn on
2. There is a tach, but when cranking it doesn't move. When I let off the start it jumps up to the first dash (about 200 RPM) for a second and then goes back down. The Service Engine Soon light turns off when cranking (turned all the way to Start)

 

I appreciate the help and response. For some reason my first reply didn't go through.

PATS
1. Yep, is flashing about every second with the truck off.
2. Yep, it comes on for about 3 seconds and then goes off.

Fuel Pump
1. About a second and a half about turning the key to RUN I can hear what sounds like a slight metal on metal rubbing coming from the fuel filler.

Check Engine Light
1. Turning to RUN the "Service Engine Soon" light comes on and stay on.
2. When I turn it all the way to start and it's cranking the tach DOES NOT move until I let off. When I let off it bounces up to about 200 rpm for half a second and then goes back to zero.

I just went to check it again to double check what the "Service Engine Soon" light looked like when I cranked it and it fired up! This was after not starting for 2-3 weeks, trying 4-5 different days over that time. I'm still not convinced there isn't an issue.

 

Ugh.. Welcome to "intermittent-ville" where grey hairs, hair pulling (if any left) and banging head against the wall are all prevalent.

Keep an eye out for any additional data.