Engine Dies while Idling

[Yeager]

Why would I lose spark while my engine is idling? I crank the car in the morning and let idle and once it reaches about 130 F it loses spark and will not restart until it cools off. I know it does not spark by using a timing light on the coil and plug wires. Also, my plugs are extremely black showing signs of a weak ignition.

I have a 74 with Permatune CDI (silver), Bosch Coil, Beru Wires, Petronix igniter, and Bosch distributer.

I have done several tests and do not see a reason why my ignition is bad (weak). I am thinking of buying a new set of wires - I currently have the Berus. I am not sure how old they are. I'm hesitant on replacing them because they all ohm out to 3950 to 4000 ohms, and I do not see any light show at night. I am also considering buying a new Bosch coil but again it ohms out to spec. The permatune box seems to be fine and I have power to it. I do not seem to have any ground loop problems. All of my tests give me 1/2 ohm or less.

Why would I lose spark at the coil with an increase in engine temperature?

Thanks again,
Mike

BTW - I posted something similar to this the other day but now my problem has changed a little.

[jstobo]

Permatune failure with heat. The silver ones are infamous for this problem. Do a search Early S man has a diagnistic procedure that you can use to check the Permatune. i would check it cold and then check it when your spark fails. This should tell you if it is the Permatune.

[rtoler]

Hi,
Did you ever figure out the problem? Was it the permatune box? I have a '77 with a 2.7 and permatune box. I have a similar problem only sometimes the car keep running even though it gets hot. Sometimes it just quits while driving. Sometimes it wont start after sitting for about an hour after having driven it home from work or other short trips. I've been told that I might have low fuel pressure, but I have no idea at this point.
Thanks,
Roger