I have a 2000 Chevy z71 and in the mornings it fires up fine. Later in the day when i turn the switch over it usually takes 3-4 second before it will start. I have put 4 fuel pumps in the truck in the past 3 1/2 yrs. I have changed the fuel filters. Also while going down the road (It don't do it all of the time) it will start to spit/sputter....almost as if it is not getting any fuel. It will finally catch and go back to running like normal. Has anyone ever had this similar problem???

 

what kind of pumps did you use and how often do you change the filter?

 

Try your injectors or your fuel pressure regulator. Next time you fill up put some Lucas fuel treatment in it and that could clean it out