Regulator, ignition coil and unknown box!

[Andrew77]

Hi, Please can anyone help?
Could anyone tell/show me what wires go to the ignition coil in a 1968 912? I have 2 red wires going to it, one of which seems to go into the wiring loom and I think goes on to the battery, and the other goes to a black box, which is bolted on to the side of the car forward of the regulator. This box has been painted black, so I can't really see what it is. At some point the wire has been reconnected halfway along with a black wire, which is obviously wrong - the original was red. Please could you let me know what this box is, and what he writing should be?

Any help much appreciated. Many thanks
Andrew

[WFBowen]

Andrew
Any chance of some photos of the box?
Bill

[Andrew77]

Hi,

Here's some photos that show the 'black box' and the wiring on the coil.

Many thanks

Andrew

[Jaems]

It is probably as aftermarket CD (Capacitive Discharge Ignition) unit. It is not one of the Bosch, "Permatune" or Ignitor CD units.

[Andrew77]

Thank you for that. However, please now imagine you are talking to an idiot! Please can you explain that again in simple terms!!! Thank you!!

[JT912]

It is a spark hopper upper. Is that better?

[Tony V]

Since the car is a '68, didn't it have some electrical contraptions to control the throttle compensator?
(mounted to the right of the coil)
Looks like it may have been painted over but looks familiar.

[WFBowen]

Tony:
I think you're correct. It is part of the throttle valve compensator system which IIRC holds the throttle slightly open when coasting or with overrun. There was also a function connected with this that cut the ignition on overrun at a certain high rpm and then resumed ignition at a lower rpm but that might have been with a 911L that I drove back then. The first picture I posted is of that compensator valve. Even if the valve is removed, a 68 should have an extra ball fitting on the throttle crossbar on the backside of the fan shroud. I'm not sure if there's a 68 out there that still has its functioning smog control system, but someone just might be able to shed some more detail on this.
Andrew:
If you care to investigate, remove the box from the chassis and look underneath and see if it resembles anything like the following (you might need a little lacquer thinner to read the numbers if it was painted on the bottom.) Porsche number is 902 615 113 00, Bosch 0 336 611 004.
Bill

[Andrew77]

thank you. I will take a proper look at the weekend, but it does sound like it could be this.

Also, there are 2 red wires going to the coil; on most I have looked there is only one - does this seek ok? The reason I am asking is that something is blowing fuse 1 (25amp) as soon as I turn the ignition.

Any thoughts welcome.
Thanks for all the help so far...
Andrew