I have a 2002 duramax that has 116,000 miles on it. I have had the injectors replaced twice under the 100,000 mile mark. I have kept it plugged in at night, changed the fuel filter every 10,000 miles and put power service antigel in the tank with fill up. Now it doesn't want to start right away. It will start after 20 minutes to an hour. I ran it for an hour, shut it down and it wouldn't start back up. I think it may have something to do with the fuel pickup. Any suggestions or help would be wonderful. Thanks Jeff