i've had the same problem with this car for some time now. i'll go through, fix the stuff, then have the same symptoms again about a month later. it is an '84 z28, with a h.o. 305, totally stock.

here is the "problem" that i'm having: i'll start the car in the morning, drive it around, park it for about an hour, then come out and try to start it without any luck. wait a few minutes, then it starts up. now, i've gone through and replaced everything from the plugs to the alternator to the ignition module. when i took the cover off the coil, one of the wires, the yellow one, was crispified and melted to the black wire. so i replaced it, and the same problem came back about a month later. got a new coil, used electrical tape on the metal bar around the coil, and installed it back into the distributor.

now, here's the weird part: there is an arc between the yellow wire and the part of the metal bar exposed closest to the coil (in an area that i couldn't get to with tape). it doesn't affect the drivability of the car, i.e. idles fine, revs fine, gauges read fine, etc. the problem is that the yellow rubber around the wire is melted and the arc has melted the area around the coil itself.

what could be causing this?

 

Have you checked the wires that plug into the distributor car to see if there is a short somewhere that would cause the arcing?

 

not yet. i'll check them once i get home today. i'll also have to get a new coil.

by the way, there are 5 wires that plug into the distributor, right? 3 of them that run from the distributor into the cap, one that comes from the battery, and one that comes from the tack. i just want to make sure that that is all of them, and that i'm not missing any.

 

Actually if I am reading my manual right for your car there are six wires total. A pink one goes to the ignition switch (bat), a black one goes to the tachometer filter where it becomes a white wire going to the tachometer. That is two of them, there are four wires in the connector that plugs into the distributor cap. Pin "A" is white wire going to pin "12" of the ECM (spark timing output), pin "B" is a purple/white wire going to pin "10" of the ECM (distributor reference pulse input), pin "C" is a tan wire going to pin "11" of the ECM (ignition module bypass output), pin "D" is a black/red wire going to pin "13" of the ECM (ground). BTW, pins "B" & "D" pass through a grounded shield that is connected to pin "22" of the ECM before connecting to the ECM themselves. That shield acts to drain off excessive HEI energy from the wires. Here is a schematic of it.