P0087 - Low fuel rail pressure - Intermittent

[Hareetr]

Been fighting this issue for a while now and need some advice!
MK6 GTI 2.0 TSI CCZB 2012

Part changed

OEM Lpfp (DB revision)
Lpfp module
G247 Bosch fuel rail sensor (the original was black, superseded with orange sensor ?)
OEM HPFP (latest revision L)
OEM CAM ROLLER (latest revision)
OEM REV G Changed from GFB DV+
OEM FUEL FILTER (6.6 bar)
PCV valve changed
Intake valves, Rubber guides & Injector cleaned
Precat Lambda changed
All 4 injectors changed
Tested low fuel with gauge (4.5-5bar) when ignition turned.

Car is stage 2 mapped, Thought it could be a map issue, went back to stock and the issue still occurred.
Symptoms -
Hard stutter (fuel cut) when WOT
Generally between 2-4k rpm between (4/5/6th) gear
I've live logged to watch the fuel rail, it asks for 150, it delivers it for a few seconds and sometimes drops as low as 15bar, and then a little later after struggling catches itself.
However when partial throttle fuel rail holds pressure with no issues and no codes.

Another main concern is the ECU, it has been supposedly flashed 30 times, with only 16 successful.

If anyone could shed some light, much would be appreciated.

Please see attached

 

[Joe_Mama]

Damn that is really strange. I assume you have checked the fuel lines running the length of the car for kinks or damage?

Very odd. Is it possible you got really unlucky and got a defective HPFP?

However when partial throttle fuel rail holds pressure with no issues and no codes.

This does make it sound like a map/software problem... but you said youve flashed back to stock and had the same issue, so that shouldnt be it...

Very weird man.

 

[Hareetr]

Damn that is really strange. I assume you have checked the fuel lines running the length of the car for kinks or damage?

Very odd. Is it possible you got really unlucky and got a defective HPFP?



This does make it sound like a map/software problem... but you said youve flashed back to stock and had the same issue, so that shouldnt be it...

Very weird man.

Yeah its really weird!!

it will hold perfectly on partial, but as soon as you WOT it shits itself!

Might be wise to swap another HPFP and see..

someone else has also pointed to the TB and or accelerator pedal.

I have posted up some logs. (not sure why i cant upload excel file, so heres some TXT) if anyone could understand anymore please let me know!

 

[Hareetr]

Damn that is really strange. I assume you have checked the fuel lines running the length of the car for kinks or damage?

Very odd. Is it possible you got really unlucky and got a defective HPFP?



This does make it sound like a map/software problem... but you said youve flashed back to stock and had the same issue, so that shouldnt be it...

Very weird man.

Swapped the HPFP, still stutters and rail drops on WOT, considering the whole fuel system has been changed, im swaying towards the throttle pedal, as i did see it drop from 99% to 33% when my foot never left the floor, or the ECU's PCM...

TB alignment seems fine.

 

[GolfRfrontend]

Check throttle body adaptation is correct and check low and high pressure values actual vs specified. If all check it out I suspect related to you tune.

 

[Hareetr]

Check throttle body adaptation is correct and check low and high pressure values actual vs specified. If all check it out I suspect related to you tune.

Hi,
Sorry been a while. All sorted now, after changing pretty much the whole fuel line parts etc cleaned all intake valves etc, turned out the ECU was at fault. Replaced the ECU, drove on stock tune for a week, no issues, loaded the tune up and the cars been running smooth since. I believe the PCM control module was not functioning correctly causing the fuel cuts

 

[GolfRfrontend]

Glad you sorted it. Very difficult to diagnose when your car is tuned, but likely always related tune.