Are you referring to fuel pressure or something different?
If it's fuel pressure, there could be dirt near the bottom of the tank that is preventing fuel from going through the fuel sock at the bottom of the fuel pump. Does the problem happen at any other time? For example, if you have a full tank of gas, does it happen?
Keep in mind, you may have a fuel pump that is simply going bad. If the vehicle was presented to me for testing, I would start by checking fuel pump pressure. Here is a link that shows how that's done:
Let me know.
Saturday, September 19th, 2020 AT 6:30 PM