Heat and Spark pluggs

[KYGTP]

I have a question for you guys, can the heat coming off of a noncoated header mess with plug wires, and possibly cause misfires?? A stock style plug wire that is, nothing special on the wires.

It is a long story, but I was dealing with misfires after my header install, I ended up replacing my PCM and putting on boot protectors, and it seem to have sovled the problem when I was at the Dyno the other weekend. But I did two things at once, so I don't know what really fixed it, the protectors, or the new/old PCM.

[PKFIRE]

Did your plug wires show any type of wear?

Melting, cracked insulation, loose boot and etc.

You're dealing with a high load of voltage and it will find the easiest path. I don't think the resistivity would change enough to alter the spark. Though a smaller gauge wire would show less resistivity change due to heat.

[plated]

swapp out another set of wires just so you can eliminate that,and go from there?

[aperacer]

put some socks on them...

[KYGTP]

Did your plug wires show any type of wear?

Melting, cracked insulation, loose boot and etc.

You're dealing with a high load of voltage and it will find the easiest path. I don't think the resistivity would change enough to alter the spark. Though a smaller gauge wire would show less resistivity change due to heat.

No, they were new wires, stock replacements, so kinda small.


swapp out another set of wires just so you can eliminate that,and go from there?

We did with a larger set and it seemed to work, so I thought that it was bad wires, so I changed out to new ones and still had misfires.


put some socks on them...

That is what I did when we were at Cincy Speed for the dyno on Sat. but I also changed out the PCM too. So far so good, but more than anything, I did not know if the Heat from headers could cause possibly cause misfires.

[PKFIRE]

I'm guessing you're running colder plugs with a small gap. You think you were having sparkplug blowout?

[Jeff88coupe]

I wouldn't think that it's the heat...but more so spark jumping from the boots to the headers that would cause a misfire. But if you have swapped wires and put boot socks on them...that shouldn't be a problem. I would be worried about spark blow out if your still running stock coils. What is your spark plug gap..maybe tighten it up some.

[kennebellcobra]

Look at them close at night and watch for the spark to jump...I've seen them look like fire works before:lol:

[Stangman]

When I had Ford Racing wires on my car (didnt have them on long) the freakin things were spark jumping like crazy... took my hood light out to see an episode of star wars! switched to MSD wires and have had no issues.

[Kwik92GT]

Pop the other PCM back in and see if the miss comes back? :dunno:

[KYGTP]

I'm guessing you're running colder plugs with a small gap. You think you were having sparkplug blowout?

That was one thought, because I did put new plugs in, autolite 103s and had them gapped at .050, still had the misfires, went to .045 gap, swithed PCMs and boot proctors on.


I wouldn't think that it's the heat...but more so spark jumping from the boots to the headers that would cause a misfire. But if you have swapped wires and put boot socks on them...that shouldn't be a problem. I would be worried about spark blow out if your still running stock coils. What is your spark plug gap..maybe tighten it up some.

I am running stock coils, but they are brand new, and the GM 3.8 coils are pretty good, beleive it or not.

I will find out tomorrow when I go to Tri-State and run the car, I am keeping my fingers crossed I have the problem fixed.


Pop the other PCM back in and see if the miss comes back? :dunno:

I think that I may have fried the PCM when I installed the headers and did not diconnect the battery, and well, I hit the header to the starter wire and almost put a hole in the new headers, so I think the grounding out mess with the PCM. I know, I should have diconnected the battery, but I was too excited to get them in. Live and learn.

[Goldenpony]

An old mechanics trick to see if you have leaky spark plug wires. Raise the hood at night with the engine idling. take a plastic spray bottle and start spraying the wires. If they're breaking down and leaking, it will look like Kings Island at night.