we replaced ign module, ign coil,distributor,ign switch and still no spark,turned out to be the ecm relay, we think water somehow leaked in from the windshield or door jam,we took the relay apart,water inside it ,all rusted out internally,,this is my buddies 92 stang originally it was a four cyl,,told him that is why i like carbed motors,no ecm garbage but then again efi is very reliable also,i converted to carb for the wiring simplicity,no speggetti