Hi all, concerned code p1191 fuel pressure system malfunction live data idle 9300 kpa expected 5000 kpa idle readings after wot test 380kpa. Road tested and all readings normal between expected and actual data until floored hard, pressure then drops rapidly sometimes falling into limp home mode.Low pressure ok under all conditions flow good too. Starting to think seems more like pressure regulator than pump?

Thanks Andrew

Andrew.
Try a forum search, there is also a TSB on problem,s with this system, modified pressure reg. and ECU updates.
Kev.

FIXED Changed regulator first but pump fixed the problem interestingly had low pressure gauge connected at all times through testing when I had high fuel pressure at idle there was no chattering and a steady pressure maintained after fitting new regulator high pressure was bang on at 5000kpa and low pressure gauge needle started to bounce around again.Excess fuel from high pressure returns to low pressure side I believe this to be a good test to check high pressure regulator

i have replaced loads of these pressure regs in the past, they were modified parts, if i can remember correctly vauxhall were on watchdog about the failure of this system were pumps and regs were replaced, vauxhall since dropped the replacement of the pump and used modified regs, i have not had any back yet, hope this helps.

I know about the modified pressure reg. and ECU updates but its normaly the pump, I grabbed this picture from another forum.

The pressure is lost through the hole in the plate