Hey so I've been trying to chase down a hesitation . In the process of checking for crossfire I didn't see any arcing on the plug wires but when I look through the fender well at where the plugs go into the head I can see them each lighting up a blue glow on the ceramic insulators ?? I changed my plugs and wires with good quality ( so I'm told ) ones but it still does it ! I can see the odd small spark on the wires in random spots but not cross fire . Nobody seems to have any idea why this is happening and I'm at a loss my self . Hopefully some one here might have some ideas .. Thanks

 

If you're seeing arcing at the wires, then they don't have good enough insulation...

 

Change the wires- even new "good ones" can be that way anymore...
Scott

 

Ok , is there a wire brand you guys would recommend ? I just put msd brand in there and they were quite expensive . Would a lousy ground cause this to happen ? I can't really see it on the drivers side but the passenger side is bad and that happens to be where I have a leaking exhaust manifold not sure if that means anything

 

Basically what is happening is the spark itself is defeating the insulation, and traveling along the outside of the wire... Usually found with defective or old insulation. I'd recommend getting factory wires over after market, but that is just my preference...

A ground will not affect this at all- The spark riding outside the insulation is simply looking for a ground: it is supposed to find it through the plug: grounding the outside of the wire would take the spark away entirely... Another way to check it is to mist water from a spray bottle over the wires & the light show should increase. Just be careful... Shocks can be no fun...

Scott

 

Ok thanks for the info guys . I will grab a set of stock wires and see what happens . I've just never seen it happening right where the plugs go into the heads . Hopefully this will work . How much dielectric grease do you normally use ? I usually just dab some in the boot hole but I feel like I'm half assing it lol

 

A little dielectric grease in the end of the boot is fine-don't need a lot: just enough to smear around the insulator of the plug once it goes on...

 

When you say stock wires do you mean from Ford or just not fancy wires ? Just want to make sure I don't keep buying wires that I can't return . This will be set # 3 .. If it does it again I'm gonna be arcing

 

How close are the wires to the headers? They could be melting from heat. Personally, I do not like MSD products. Any OEM wire should be fine. If it keeps happening you may want to look into what component is causing enough excess current to break down your wires. Like a failing coil.

 

I personally usually prefer factory- Ford- wires: they were made specifically to their design, so should be able to handle whatever is coming out of the distributor, and the material quality should be beyond reproach...

From what you describe, it sounds like the aftermarket insulation has broken down, and is allowing the electric current to leak out, causing the arcing... Remember: Ford is using a high-energy type ignition coil in this system: If the amount of energy discharged through the distributor to the plugs is greater than the insulation can handle(as in the case of non-HEI capable wires used in the application) then this can result... And, depending on the chemical composition of the boots, if made with cheap materials, they themselves may have a conductive quality...

I just reread the entire thread, and while the whole wire may not be leaking, that "blue glow" at the plugs sounds like the issue is in the wires... But it is hard to diagnose 100% without actually seeing it: however, I've given my best educated guess, and would say the wires are just not up to the job. Next question is, what kind of plugs are you running? Motorcraft, Autolite, Champion(toss them), Delco, NGK, Bosch? I usually recommend Motorcraft or Autolite for Fords for obvious reasons- they were from the manufacturer of the vehicle, and should meet their standards...

Scott

 

Thanks so much for your help . I just bought a set of ngk wires and will put them on tonight . I put a new coil on when I did the plugs and wires as well . The plugs are motorcraft . Will let you know what I find out 😉

 

Hey so I replaced the wires and it's still doing the same thing ... I'm starting to wonder if maybe my exhaust manifold leaking is maybe to blame ? It seems to be mostly happening on the passenger side and the leaky manifold is quite audible . Could it be carbon leaking and causing the arcing ? I've also read on a few non Ford sites that running lean can cause this , I have no idea how though . I'm stumped . The last thing I want to do is try to get that exhaust manifold off

 

I would bring those wires back and go with stock wires from Ford

 

I'm just not understanding how three different sets of wires are doing the same thing . It's like the air around the ceramic insulator on the plug is being charged . Would it be too far out there to think the exhaust leak could be creating a carbon mist sorta speak ?

 

The wires aren't the problem here as you've discovered, (except for maybe your wallet.) For whatever reason the secondary voltage likes the manifold more than the plug gap. If they are the proper plugs and gapped correctly, then something else is going on.