I did this.
1- Pipes from fuel tank to fuel filter and then to fuel pump inlet. If any of these pipes are leak, even slightly, engine doesn't start at all. This is what i experienced multiple times, but i might be wrong.
2- checked all pipes in engine bay first and bent them to see cracks. The pipe photo i attached looked perfect in straight, but it showed cracks upon bending.
3- i replaced faulty plastic fuel cap and now no more petrol smell.
4- as a precautionary measure, i used several tie bands to tie fuel pipes, vacuum pipes, wires, relays etc, so that they don't touch hot parts like radiator hoses, hot metallic parts etc.