no fire at plugs

[byron]

Need some help. No fire at plugs, any ideas. Vehicle will start on one occasion and not on another. Seems to do better after an overnight rest.

 

[BradE.]

Start with coilpacks and new wires.

 

[410Fortune]

Check the wiring harness going into the coil pack.

I have seen these loose MANY times causing a problem like you describe, ESPECIALLY on the 97-98 SOHC 4.0L engine's........pull the wires from the coil pack (not the plug wires, the computer harness wires) clean up the connector with WD-40, check the wires to make sure they are in tight, plug it back in and make sure it snaps into place.....


Next thing to check would be the coil pack itself.
Then look at the motocraft timing controller (near pass headlight). I have never seen one of these fail

After that you might check the computer itself (plug in a friends). I have seen several computers fail in the last couple years, mostly pre 95 Explorers (age?)

I assume:
starter is cranking
fuel pump is on
you have tested for spark in both banks? (from coil pack, 2 sides)

If you have a CEL get the codes pulled.
Most likely it is loose/bad wiring or a bad coil pack.