It dies when you turned off the key , gas gauge still up until you do turn off the key then turn key back on and it don't come up and won't start until gauge does come up, sometime you can move wires on computer and it helps, sometimes not

The first time this problem started it was simply annoying. The second got a little worrisome. Then when It wouldn't start it was a real bother. An older car I could have probably fixed, but with the computer stuff, I haven't got a clue. Any suggestions would be appreciated