Noise from the bottom rear on the driver side on 2001 Yukon

I've been noticing a humming or whining noise coming from the rear of my truck while it's running at a stand still and moving. When I turn the truck off and turn the key half way I can hear the little whistle noise again. But after I turn it halfway 2 more times, it don't do it. But when crank the truck up, about 10 seconds later the noise happen again. Also my truck is hesitating when I'm at a stand still, but while I'm driving it's not doing it. Is it cheap gas or something? The rpm don't move. It's sounds like it want to cut-off but don't.

I have the same problem, I heard it could be the fuel pump. WHen you get a an answer that me know buddy.

Hi,
this may help troubleshooting:
The fuel pump will operate for 2 seconds after you have turned off the ignition.

Take care, Eggert Johnson :bananasmi