Fuel pickup problem?

[ChevyTech]

If you are sure it is an issue where the fuel pump only runs when it is warmer, then don’t bother with the coolant sensor.

When you turn the key on the fuel pump should run at least two seconds. If it won’t run, the fuel pump, relay, wiring or the computer have a problem.

I don’t think the problem is the computer. My guess would be it is the fuel pump or the connections to the fuel pump.

I suggest only using OEM (Original equipment manufacturer) fuel pumps.
I have seen so many aftermarket fuel pumps fail during their warranty, or just after the warranty expires, that I strongly suggest you stay away from aftermarket pumps.

Often when a fuel pump won’t run, if the bottom of the gas tank is hit with a rubber mallet, just as the key is turned on, the pump will run. My guess is that new pump does not want to start spinning when it is cold.