I've got 2010 Vauxhall Zafira 1.7CDTi ecoflex with idle fluctuation problem.(vehicle has done 73000 miles)
Owner ask me to look at the car as since the last servic(done by someone else so no idea what they done with it)the car starts fine even in the cold mornings and sounds nice but when the engine getting warmer idle speed begins to fluctuate.was all right before
From experience i guess too much injector leak off could calls this but i haven't got adapter for Denso injectors(bought a set from internet and will do the test when i get it)
interestingly this idle problem is intermittent.sometimes there but sometimes isn't.
Scanned it with scanner(Delphi DS 150)and rail pressure fluctuate between 210-280 bar.
DRV and IMV duty cycle value fluctuate too.both are on high pressure pump on this vehicle and i only could scope Inlet meetering valve as i was unable get to DRV.IMV changes 38-42% on idle.
Another thing is the injection event.Scoping with Pico when the car runs ok there 3 event taking place(Pilot,intermediate,main injection) but when idle fluctuate only two injection events.
looks like the ECU try to compensate something
when the owner bring the car back will do injector leak off test and take IMV off to clean it.
Any suggestions would be appreciated