Causes of coilpack melting

What is your question?

What would cause a coilpack to melt down Always same cylinder #2 4.7L V8 and it doesn’t have to run for very long. I think 3 coils have been ruined after replacing injectors plugs 02 Sensors full set of coilpacks sensors and so on Jeep is hard to start If it has been setting The PCM has been swapped Last one came from Fladship 1

How long has your 1999 Jeep Grand Cherokee had this problem?

Few months