I am having troubles with my 2004 bonneville gxp 4.6L engine... Sometimes my car wont start like it's a dead battery. I've tested the battery and it is still good. When you jump start it, it idles high. We shut it off and immediatly start it again and it idles fine. We can shut it off and restart it again 5-6 times fine. Could there be any other electrical issues?