Weird engine problem while driving to the track. Any ideas?

[Noel]

While I was driving about 3.5 hours to Nelson Ledges this past weekend (Near Cleveland), my car suddenly developed what felt like a bad miss. The car ran very rough and there was no power under acceleration. I pulled over to check the plug wires, etc and found one loose, but it didn't seem to help. I then made sure all the wires were on the distributor cap tight and my hand must have hit something around there and I got shocked. (In case this is relevant) I got back in the car and it was still missing. A couple minutes down the road, the car suddenly stopped missing and drove fine. Then it started missing again and then stopped again. The rest of the weekend at the track and the ride home, the missing never came back. Any ideas?

Thanks,

Noel

[jlex]

Noel:
I had a very similar problem with a 914 I owned back in the '70's. Was coming home late one night & experienced similar intermittent problems like yours. Luckily, it was dark... when I opened the engine compartment (with the car running) to see if I could troubleshoot anything, I noticed a bit of sparking that coincided with the rough idling. Turns out an electrical component was grounding itself against the engine tin. I remedied the problem with some electrical tape & never had a problem again.
I was lucky because it was dark outside which made the spark visible. If it had been daylight, I never would have found the problem.
I suggest you start the car up at night & look for sparks indicating an electrical short. Good luck.
regards,
jlex.

[Noel]

That is a good idea. Although it was dark for me also, I pulled into a gas station both times to diagnose the problem. I thought it sounded electrical since I got shocked. Since the car runs fine now, I'm not sure how to recreate the problem.

[jlex]

Use a thick pair of thick rubber gloves to jiggle around any suspect components or wires in the engine compartment while it's running. I'd do it in the daytime so you can see what you're doing. If you touch the right thing, the problem should come back. Pay attention to your ignition wires...could be that one's cracked. Test resistance with a digital multimeter. Also, pull the distributor cap & look for cracks & signs of arcing. Sounds electrical to me too.
regards,
jlex.

[jluetjen]

When installing plug wires on a High Voltage ignition system (such as is common in 911's), it's usually good to put a "dollup" of dielectric grease into the boot at each end of spark plug wire. This will help to prevent the ignition shorting itself on some dirt or moisture which believe it or not is possible to do. The grease helps to displace moisture.

BTW - make sure that it is clean inside each boot before putting the greese in.

[john walker's workshop]

on 76-83, i've seen a lot of plug wire arching where the metal cored heat hose lays on the #1 plug connector. move the hose away from the wire, and check condition of the wire and connector. the coil wire plug totally corrodes away on carreras sometimes.