easy enough to check....pull off vacuum hose from plenum and suck through it, if you can suck through it (or there is petrol in the hose) the diaphragm is split...make sure though, the hose itself is not split.
you could also clamp off the fuel return hose from bottom of FPR, see if your idle improves
Looks like the FPR is fine. I had already changed the small hoses.
Clamping the bottom hose - no change.
Guess I'll check for leaks again - although I already sprayed all over.
If it was a leak big enough to stall the car wouldn't it also be noticeable when the ICV was disconnected?