I have a 2000 Chevy Silverado 5.3 Liter EFI engine. It starts fine when engine is cold. After engine gets to operating temp. and you shut it off, you have to crank a long time to get it started again. Truck only has about 60 K on it. When truck was new I had to take it to the dealer a lot for throttle problems. Could this be my problem again?