normally, there is a short in one of the coils in the idle speed controller. this causes extra power to flow through the coils and into the ecu. this is too much for the chips to handle and it cooks them.
but often these ecu seem to have done the rounds, so maybe was blown before. but if they blow like the pics above, they stink for a couple of days. its gross. you know something is cooked...
1st page has details (youtube video) on checking the isc with a multimeter.
get your isc up to spec, then if that hasnt made it idle nice and even with the isc plugged in or unplugged it no different, then better look inside ecu.
