System is delphi with brown and green plugs on pump.When vehicle first came in did a pump proof test and seemed similar to what i have saved from known good vehicle.The problem is that on crank it seems to behave like a proof test,i.e pressure gradually climbs to max and stays there even after switching ignition off and then back on.On the old pump i could disconnect the imv and manually control it and pressure still wouldn't drop,as i say it seems you can only release pressure by physical means.Havn't done any pico checks on 2nd hand pump as yet.
Regards Alwyn