Sparking in engine bay

[gtrp]

Hello,

I finally fixed the vacuum leaks in my car and it starts up very nicely, however I know get a spark from this top piece to where the rubber tip meets one of the metal wires.

Is there a better way to reroute this? It is supposed to look like a mess? I'd like to clean it up while fixing the spark.


81' 911sc - Weekend Project Car
09 GTR - Race Car

[kodioneill]

You need a new set of wires if they're arcing.

[gtrp]

Simple enough, thanks.
Wasn't sure where the arc was originating from so I didn't know if the "thing" at the top with the faded stickers was bad.

What is that thing anyway?


81' 911sc - Weekend Project Car
09 GTR - Race Car

[wwest]

Long story...

For this ear of 911, lots of airboxes, 911 intake manifold, have BLOWN up.

Porsche's thinking, for your MY, was that the spark was jumping from one HV plug wire to one a HV plug wire with the intake valve OPEN.

BACKFIRE in the airbox blows it apart at the seams.

The braid was supposed to prevent this possibility.

Remove the braid.

[wildturkey]

If your plug gaps are too large you may find the spark has a tendancy to take a shorter path. Also if your lug leads are old they again may cause the spark to find a shorter path to earth.

[poorsha]

" What is that thing anyway?"

That is the ignition coil.

And as mentioned it looks like a new set of ignition wires are required.
Perhaps they will be under the Xmas tree.

[47silver]

Could just be the coil wire that feeds the distributor. I had to replace mine and the wires were only a year old. start the car up at night without any lights, and watch you will see the arc, if it is arcing at the coil replace that wire from our host. Buy 2 keep one spare.

[wwest]

The sparking is likely at the boot covering the coil center post and HV wire to the distributor. The GROUNDED wire braid is extremely close to the bottom end of the robber boot.

Check to be sure that HV wire is forced fully into the coil tower center.


Since the wire braid has a adverse effect on the spark risetime it is best eliminated.

[gtrp]

Thanks everyone, it may be time to replace them. I did move them around a bit but since I'm unsure of the age, I guess it's better to be safe.


81' 911sc - Weekend Project Car
09 GTR - Race Car

[kshafer1]

I know for sure that my wire shielding is not grounded at that point so close to the coil. I'm at work so I can't take a photo, but I believe they are grounded closer to the case.

Not mine but this pic might help:

[The cap'n]

You may "know for sure", but you're wrong. The grounds are the studs shown in the first picture in this thread, the same ones that hold the coil in position.

The Cap'n

[wwest]

It matters not where the braids are grounded, for HV spark voltage, >20,000 volts, even a high resistance "ground" will do.