Wife's '99 Expedition (5.4 V8) won't start. Turned over last night but wouldn't fire. Started fine this morning. Drove around, filled up with gas, drove home. Tried to restart about an hour later, once again it turns over but doesn't fire. I noticed the THEFT light blinks fast when I try to start, I don't remember it blinking like this. I checked the fuel cut-off swith and it was fine. I can't hear the fuel pump, but I'm not sure if this is normal. I taped on all of the relays, but I don't know which one is for the fuel pump since I don't have an owner's manuel. Any help will be greatly appreciated

 

First thing I would do is change the fuel filter. Just curious, has your rig been towed or had the front end off the ground lately?

 

Thanks Bowcop,
No, it hasn't been towed or had the front end off the ground.

 

Thanks everyone,
Turned out to be the anti-theft device in my key. We tried a different key and it started right up.