2000 Oldsmobile Bravada fuel or ignit switch probs or what?

2000 Olds Bravada How to check if fuel pump is good without pulling tank? already replaced fuel pump relay & fuel filter. after many attemps to start the pump will kick on. but fails at next try. need help on this without spending lots of cash troubleshooting...got coder & it says PASS no codes to detect..
fuel pump does not come on...till after many attempts to start or i go off & on with the key & it has came on 1 time like that...but next start attemp pump does not come on.

There are several things to check related to fuel pump operation. It sounds like you have an intermittent problem so you need to determine if the voltage going to the fuel pump is consistent at the fuel pump relay. In the underhood fuse panel, right next to the fuel pump relay is a small blank, (empty) recessed terminal. It is connected, (inside the fuse panel) to the grey wire that runs to the fuel pump. When the ignition is initially turned to the RUN position, the terminal should show battery voltage for about 2 seconds and then drop to zero. It should show battery voltage continuously when the ignition is in the START position. Post your results.