386 pete ism cummins

Ok guys so here's the problem I'm having. The truck will run great all day. Wake up turn the key on for about 20 seconds then let her fire and warm up. As I step on the throttle there is a delayed response of about. 2 seconds. (Did it in both 60* and 30* weather) I thought maybe water in my fuel so I unscrew the little valve on the fuel filter and it spits out air bubbles/ fuel. I crank it back up and it runs fine. What do u think the cause is? I'm gonna change the filter in the am if I can find someone with a filter wrench ....

 

Yes as soon as its started.... Has not done it in 6 days