65 - no spark when hot
 

Have65 small block thatstarts fine when cold. When hot there is nosparkcar. Turns over fine. Coil, cap, rotor,balllast resistor fine. Replaced wire from coil to cap. Has an electronic module in place of points/condensorbut has same problem with either set up. Have hot wired the coil and still no spark when hot. Changed ignition switch. Any thoughts?

RE: 65 - no spark when hot
 

Welcome to the forum rossi1369. You say the components are fine, how have you tested them? My first suspect is the coil, it is nothing more than a step-up transformer, transformers get warm/hot during use and if it has an internal break in one of the windings on either the primary or secondary side it will fail when it warms up. Now, you say you hot wired the coil with no luck, if you put 12 volts to the coil and have no provision to "make and break" the the input voltage you will not get a spark, you will only heat up the coil. The ignition points or the electronic control module have the job of "making and breaking" the primary (input) voltage to the coil, the coil will produce the spark when the voltage is taken away from the primary. I would re-test the coil when it is cold and then warm it up and test again. Get back with us with any new-found info and we'll go from there.

RE: 65 - no spark when hot
 

Thank you 78buckshot for your input. What I have done was bench test the existing coil as well as swapped out the coil with 2 others that were also bench tested when the car was hot and it still did not produce spark.

RE: 65 - no spark when hot
 

Well, I think the next thing I would do is put in a new set of points and condenser and when it fails again start checking for voltage to the distributor before it cools off. If your sure all of the conventional components are good then you must be loosing voltage in the wiring when it gets hot.

RE: 65 - no spark when hot
 

I replaced the distributor and tested it once before I stored for the winter season.This 1 test was positive but will know for sure in the spring when Itake it for the summer. Again, thanks for the input!