Sure this is a really stupid Q - 97 4.0 petrol - Gunsons Gas tester professional (DIY kit in UK) reading 4.5% and the car has started to smell of fuel with increasing consumption - just how do I plug WHAT into WHERE to READ and ADJUST ~~~~~~~~~~ my Reliant Scimitar has a mechanical fuel pump and carburettor so a twist here and a screw there & I'm sorted....