ya maybe a few more times and ill get lucky

The gauge on the instrumental pannel works fine when i can get the switch to change between the right and left tank. The problems:
1. When I press the switch it doesn't always switch between the tanks, only sometimes.
2. When i go to start the truck the engine turns over but doesnt run. After flicking the switch back and forth for awhile it will eventually start up. This doesnt happen daily or everytime I drive but happens a couple times a week. This will also happen after I have been driving the truck and I turn it off and try to start it up again.
I have the switch always set on the left tank because the right tank has idling problems and poor throttle response. This is after I have replaced the pump in that tank as well.
I checked the wiring that the switch plugs into and its not faulty.