Spark Plug Wire Crossfire?
 

I was just introduced to the Crossfire thing in another post I seen. I keep posting about a cold start issue but when it warms up it's fine. (I got the 5.0 V8 in a 92 F250 E4OD trans) It actually starts like it's missing a plug or something but it's tuned up completely with new wires, plugs, cap, rotor and coil. Now my question is this.... Even though I have BRAND NEW NAPA Spark Plug Wires could they still crossfire? I don't see any sparks when I open the hood in a pitch black area. Could the be crossfiring under the cap? If you wanna know all I've done and replaced you'll see it all on my previous post. But anyway I can guarantee My wires aren't routed right. I don't even think my separators exist haha! But if it is crossfire I don't know why it runs fine when warm. Thanks in advance (:

I have the same problem with my 89 F250 302/aod under load it misses, drove me nuts trying to figure it out, finaly I found this:
https://www.ford-trucks.com/user_gal...id=238366&.jpg


Took care of the problem!

Does anyone have the diagram for a '97 7.5l? I haven't seen it.

J

this link may help if your firing order is different than one pictured above.

1983 Ford Bronco TSBs & FSAs (Recalls) for '83-96 Broncos & F150s picture | SuperMotors.net

Hope this helps everyone!

I need the wire routing diagram for the '97 7.5. I'll do a search, but, while we're here, I also need it for a '78 6.6.

J

Sorry J, didn't mean to sidetrack the Post. I posted the link for JV2290. I'll look around for the wiring diagram for the 78, 6.6

No apology needed, I appreciate the help.

J

Unfortunately that wasn't my issue. I routed them correctly but It still runs bad. Thanks for the info anyway! I still learened something haha

It's an inductive crossfire between 7 and 8 usually. Inductive means the current from one wire induces a voltage/current in the adjacent wire, so you won't see any arcs between the two wires.

Apparently the firing order in that sticker (Eddiec's) is only true for 5.0 engines built from 1994 on. The firing order for older engines, like mine, is 1-5-4-2-6-3-7-8.

Old thread, but Eddie was active yesterday.

Your post above reference a picture, but the link is dead.

What did you find?

Steve

https://www.supermotors.net/getfile/...ute8793_5l.jpg
courtesy of Steve83

Thanks. Is there something similar for a 1990 460 EFI engine?

Thanks,
Steve

The 7.5L and early 5L engine share the same firing order. The diagram I posted will work for your application.

Thanks. I am going to pick up some spark plug separators and see if it helps.

I've been struggling with an intermittent stumble/miss under load at top gear at 45 MPH.

Steve