99 Explorer shutting down while driving

[Armymama4]

I have a 1999 Explorer 4.0L 4x4, It recently lost all power and shut down while driving after a short distance. We thought that it wasn't receiving fuel so we replace fuel pump and filters after it sat over night it finally started. My husband drove it to work and it was fine, when he was on his way home it did the same thing. A mechanic at work said it was the coil pack not receiving spark so that was replaced. It still didn't start; after some digging around they found the original factory key taped to the anti theft sensor near the ignition!!! Is it possible that if the battery is dead in the key that the anti theft system is causing the explorer to shut down while it is i drive and not start back up? If not what could the problem be?

 

[1998Exp]

No, to the best of my knowledge the transponder in the key fob is passive (has no battery). Most likely a previous owner lost the second key. In such case making a new one is a fairly expensive dealer-only thing, so they just taped the only one under the dash. It's a common trick, albeit it defeats the PATS system, rendering the vehicle very easy to steal.

As for the no start, instead of randomly replacing parts, I would recommend following a step-by-step procedure. It's been posted here several times -- use the search function. Good Luck!

I have a 1999 Explorer 4.0L 4x4, It recently lost all power and shut down while driving after a short distance. We thought that it wasn't receiving fuel so we replace fuel pump and filters after it sat over night it finally started. My husband drove it to work and it was fine, when he was on his way home it did the same thing. A mechanic at work said it was the coil pack not receiving spark so that was replaced. It still didn't start; after some digging around they found the original factory key taped to the anti theft sensor near the ignition!!! Is it possible that if the battery is dead in the key that the anti theft system is causing the explorer to shut down while it is i drive and not start back up? If not what could the problem be?

 

[JusTheUsual]

check the fluid level on antifreeze. My freeze plug went which leaked radiator fluid all over. So the sensor that reads hotness of fluid always stayed at right level at middle of gage and it overheated and shut down. The engine would not start if hot hence why it wouldn't start right away. So I'm just throwing this out there just in case of why it wont start and it died

 

[J_C]

Yeah the key has no battery, instead a small coil inside generates power for it, energized by a magnetic coil in the steering column.

Even if it was a new style replacement key with the remote buttons built in, the battery would just power the remote feature and it would still have the battery-less module for the security function.

Try using the factory key, see if it starts and/or shuts down still.