friends 94 lesabre has a high idle problem. code read quad driver failure. cleared and no codes came back vehicle will start and then go high idle, when you shut engine off you may have to wait 10 to 20 minutes before engine will restart. suspected bad idle air control valve and replaced that part but problem still there . engine had a heavy vacuum sound checked for loose vacuum hoses and found none. any help would be greatly appreciated

 

just want to let everybody know that i replaced the ecm on the vehicle and that solved the problem , it also solved the no speedometer problem the car had .