When switching to the ignition mode I heard a very weird hissing sound coming from the fuel pressure regulator. It sounds just like an air leak.

When I heard this sound the engine wasn't running so there was no vacuum or boost avaible or whatsoever. It came straight out of the fuel pressure regulator like the petrol was pumping very hard through it.

My mate was also there with his 2wd sapp and we checked if he also had this noice but his fuel regulator was dead quiet.

So has someone got the same experience and can confirm if the regulator is defect when producing such a noice?

It's a Sierra Cosworth 4x4 I have got.