I have a 98 F-150 with the 4.6L. Found a dead wire yesterday and replaced them with a new set from MSD. Now it's crossfiring under acceleration. I ran into this problem with my Cobra with certain wires routed close to other wires. Anyone know of the correct routing?

 

I've never heard of any late model ignition wires crossfiring, that's weird. Anyways if you can't figure out how they were routed from the factory i would go to autozone and get some cheap wire looms to keep them spaced out. They're only like 5 bucks for nice chrome ones, and remember, chrome adds 15 horsepower

-jon

 

I had my 97 4.6 do something like that. I opened the hood at night and saw what I can only describe as round rings traveling through the wire, like it was translucent. I know that sounds weird, it even looks weider. They were moving fast. I replaced all the wires and still did the same thing. Put new plugs and silicone greased the wires and no problems. Third set of Motorcraft wires and plugs and 177K miles.