When you try to start it several times and it dies, go back to the tailpipe and take a good whiff. Does it smell like raw fuel or no fuel?
A new gas cap, filter + pcv would be cheap even if it didn't fix it. Can you swap caps with somebody temporarily?
Without trying to sound too erotic, I don't think fingering the hole is doing anything. At least not for the VX.
More likely the removing of the gas cap.
Another option when it doesn't start right off, might be to turn the key to on, not start. Get a rag and go under the hood and depress the schrader valve on the fuel rail, remembering that the fuel should be under pressure, 30- 40lbs. Does fuel come out?
When you say you have to hold the pedal down to get it to start, do you mean hold it at wide open throttle (clear flood) position or just hold it slightly more open than idle position?