Car wont start!?

Got a clio 197. Push the brake and the start button as you do, car starts, idles for a second, then cuts out. Car will only stay on if I put revs in then as soon as I let go of the accelerator it cuts out. Any ideas as to ehat is causing this? If so is it gonna be costly?
 
Guessing a sensor, Idle control valve? Knock sensor? Or lambda sensor


or coil pack, leads or spark plugs
 
Diagnostic wouldn't connect, guessing you need a reno specialist tester. Coil packs arent wet either

if its keyless system then the obd2 wont be getting an ignition signal....

unlock - put keycard in dash slot - don't touch pedals - press start button until dash lights up and steering lock clicks off - ignition is now on