So the last couple days if I let my car idle for more than 20 min I have to jump it to start it. If I don't let it idle its fine. Any ideas what could be going on?
2005 4.0l auto
93 F250 3k in rebuilt 460
03 Xterra on 32s-stock for now
2005 Mustang-stock for now
An under-drive pulley will run your alternator at a slower than "normal" speed if you have one. Thus the possibility of it not charging fast enough when you leave it idle for a long period. 20 minutes still sounds awfully quick even for an under-drive pulley scenario. Have auto zone check your battery. Do they check alternators too? Ask them to do that too if they do.
An under-drive pulley will run your alternator at a slower than "normal" speed if you have one. Thus the possibility of it not charging fast enough when you leave it idle for a long period. 20 minutes still sounds awfully quick even for an under-drive pulley scenario. Have auto zone check your battery. Do they check alternators too? Ask them to do that too if they do.
Have you checked for the loos battery connections. Because mostly this is the main reason for this kind of problems.. I think you should check that once. and I hope you will find the problem from there. Good Luck.