What should the rail pressure be? MK5 GTI 2.0t BPY

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Roh Echt

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I have been trying to find out what the rail pressure should be when cold. I was experiencing a slight stumble at start-up and one thing that came up was a leaky injector. So, since I thought fuel pressure in the rail should be trapped due to the hpfp outlet valve, the fprv (pressure relief valve), and the injectors...I thought that perhaps if I could see what others rail pressure was when cool that I may be able to determine if I have a leaking problem. My rail pressure was 6.4 bar...another replied his was 25 to 30 bar...while others replied about 7 bar. I know temp and condition of the bits I mentioned to contain the pressure are all factors...but should it be as low as I or others are seeing? Or should it be a bit higher...more in line with the one seeing 25 to 30 bar? I know I can look into each cylinder with my bore-scope to look for fuel or perhaps I can dab a cotton swab into each until it contacts a piston...but I would likely have to go by smell as I am pretty sure some fuel would seep past the rings when sitting.

Notes: My actual rail pressures do not lag or go out of spec range when compared to the target pressures when I do data logs from 2k rpm to redline. My LTFT off-idle is at about +8%...while nothing out of spec for the LTFT @ idle = being within ±1% even after a "clear codes" is done.
LTFT off-idle +8%; I know I have a leak somewhere near the turbo...smoke tested proves this. I just haven't been able to find exactly from where the smoke comes from as I cannot get a steady stream to come from the leak so to find it. I've tested three times now with three different versions of a smoke tester and all give me whisps of smoke from the area but not well enough for me to find it yet.
 
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Jef

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When requesting assistance, include a full Auto-Scan.

Your rail pressure at idle should be around 50-ish BAR. Generally speaking, rail pressure is a bit higher on a cold start for a brief time, then it will settle down to the normal @ idle pressure.

What Measuring Value Block data are you looking at and under what conditions? Key on/engine off? Idle? Hot? Cold?
 
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