I was gonna say fuel pump going out but thats out of the question?
If it was the IAC it would still start once you hit the gas which will let some air in the intake and let it start which is what the iac does. Happened to me many times cuz the clip that holds the connector onto my iac is missing so it disconnects after I hit some bumps and then it will idle wherever I set the base idle and wont start unless I open up the throttle a little.
It's on and off really. Sometimes when I let off the clutch it starts. (this is when the car is moving btw)