Fuel Pump running

Any ideas. I have come out to my truck in the morning to go to work and hear what sounds like the fuel pump running. It starts without any problems, but like any other problem, in order for Toyota to warranty it, they have to witness it. It has done it 4 times since I have owned the truck, roughly 4+ years. It is out of warranty now, but I would still like to know what might be causing this to happen. Other than that, the truck is great. Any thoughts on this? I have not done any mods on the truck and have only replaced the battery 2 times, under warranty done by Toyota dealer. Help me out

 

Not a fuel pump.

It’s an air pump for emission system, totally normal.

 

I think you are hearing the vacuum purge of the fuel vapor system. It's normal.

 

Like I said, no problems but it is nice to hear what the cause might be. Thank you.

 

Yep. These guys are right. I've heard that running many times in my quiet garage at night.