Self revving after 2nd start of the day

[JesterPgh]

This was a first for me. When I started the truck for the 2nd time today, it ran up rpms without any input from me. It didn't go nuts, but it went up by at least a few hundred rpm over normal, and it did it by itself. This lasted maybe 15 to 20 seconds, then settled back to normal idle.
Is this normal? Or is this a problem? If it's a problem, what should I look at?

 

[Russ]

Sounds like air in the fuel lines. How old are the return lines and o-rings?

 

[JesterPgh]

I have no idea. Aside from the new clutch, a few small odds and ends, and a spring hanger going on it tomorrow, this truck is as I bought it a week or so ago. This was the only time it's happened, never happened before this, and hasn't happened since.

 

[towcat]

Sounds like air in the fuel lines. How old are the return lines and o-rings?

+1