Can anyone confirm that the fuel pump is ok with these pressures or do I need a pressure test to confirm the low pressure fuel pump or module are hosed? Seems to me that low pressure is ok. If low pressure is ok then on the high pressure side the hpfp’s are the likely culprits; however since one fuel distributor was already replaced could this also be the issue? Any insight? Thanks! I did find some used hpfp’s from poland for $73/ea - ha. Probably in for ~$320/pump in the states. 
wasnt able to get the logs to look at but here are a few things.
The LPFP if the rail pressure before the HPFP is too low then the intank pump needs to be updated. If the rail pressure after the HPFP is below specified then HPFP. Its a lean code off idle that usually is the HPFP or some sort of fuel related issue that could tie back into the injectors. Since it says you replaced the one bank with all new injectors I would lean more on the HPFP side.
So reading 140 at idle shows the following, pasted at full accel right after. The requested psi on left and then actual on right. Can these values show that the LowPFP is ok? I need to check what the expected psi is, but I thought it was around 6 or so. So if I’m in the teens (lowest at ~5.5) can I confirm low pressure side is ok? Trying to figure out if I need to go get a fuel pressure test or if I should just order two fuel pumps - unless I can test them individually.
140 @ Idle
35 13.93
35 13.94
35 14.03
35 14.1
35 14.1
35 14.1
35 14.1
35 14.11
35 14.23
35 14.27
35 14.27
35 14.33
35 14.36
35 14.34
35 14.44
35 14.45
35 14.45
35 14.6
35 9.8
30 6.35
30 7.7
30 7.83
30 7.9
30 8.45
30 10.37
30 9.07
30 7.68
30.38 6.83
30.02 6.72
30.16 6.82
30.27 6.4
30.41 6.48
30.63 6.23
30.97 6.26
31.45 6.36
31.73 6.16
31.97 6.15
32.13 6.16
32.06 6.08
32.04 6.08
32.13 5.67
32.14 6.03
32.12 5.72
31.98 5.49
32.01 5.57
31.99 5.57
32.02 6.37
31.98 6.85
31.93 6.93
31.93 6.98
31.91 6.87
31.88 6.83
31.86 6.73
31.81 6.91
31.78 6.56
31.67 7.04
31.57 7.24
31.56 7.3
31.52 7.05
31.48 7.3
31.46 7.38
31.4 7.3
31.36 7.1
31.33 7.23
31.3 7.04
31.24 7.41
31.19 7.34
31.17 7.1
31.14 7.35
31.14 7.27
31.13 7.18
31.14 7.22
31.09 7.32
31.09 7.37
31.08 7.33
31.08 7.24
31.07 7.09
31.07 7.15
31.05 7.25
31.03 7.13
140 @ full acceleration (until top of second gear)
34.96 7.43
35.51 7.25
36.6 7.3
36.46 7.25
38.07 7.34
43.69 7.85
57.11 7.61
64.24 7.37
67.02 7.03
77.99 6.65
91.71 6.72
96.26 6.5
100 6.55
100 6.6
94.65 7.27
79.19 6.87
82.95 6.94
83.44 6.95
69.17 6.99
71.21 6.95
66.17 7.02
61.27 7.27
56.82 7.47
55.58 7.52
54.21 7.72
48.54 7.94
Your high pressure fuel pumps are obviously dead. 5-6.5 bar is the max that the low side pump can push so the high pressure pumps are not building pressure. It might show 7 bar but most likely the high pressure pumps are still dead. I would replace both as a set because when one high side pump dies then the other tries to compensate until it dies quickly there after.
Cheers Jimmy. At least it’s a diy and I’ve already done just about everyting else. You think I should service 6,7,8 & 9 injectors first or doesn’t really matter?
Think I should do the cam followers at the same time?
Bringing up old thread to ask how one collects the data shown in post #22.
I too have P0087 codes in the 01-Engine module. 11-Engine module has no codes. CEL and EPC light with just no power on moderate or greater throttle. Stumble if you try to punch it. Feels as if it is starved of fuel.
Thinking HPFP. Which side if codes are on the 01-Engine, L or R?
Again, would like to data log to confirm. Have VCDS.
Thanks for the help.
It is group 140 for target and actual fuel pressures.
The pumps are plumbed in parallel and we only have one high fuel pressure sensor so you cannot distinguish between left and right using any pressure data that you get.
Thanks.
Alright, reading up on data logging here:
http://www.vaglinks.com/OBDII/Vag-com_Data_Logging_And_Graphing.pdf
Will give it a try tomorrow and will report back.
ok, data-logged group 140 (BTW, steering angle is in the 1st block, is that right?).
I’ll post the raw data in the next post, but here’s what I think I learned:
–fuel cannot reach the commanded pressure when requested by moderate throttle input
–this arises when the engine is cold only, and once engine reaches operating temperature there are no issues.
Why do I say this? I cleared engine codes, then logged data with engine at idle with no issues (see data set 1). Then I logged data during a WOT run and the EPC light came on and there was no power. Fuel pressure could not keep up (see data set 2). I tried a couple more WOT runs with EPC light on and with the same result. I then cleared the codes, but engine was up to operating temperature on the gauge. I did a few more WOT runs, but could not get the EPC light on or the issue to reproduce itself. (see data set 3).
So for now, this is an cold engine issue. Thoughts on what the issue is? Are there other data groups I should log?
Data set 1:
30.35 30.01
30.35 29.77
30.35 30.14
30.35 29.93
30.35 29.76
30.35 30.13
30.35 29.84
30.35 29.63
30.35 30.15
30.35 30.02
30.35 29.7
30.35 30.29
30.35 30.18
30.35 30.04
30.35 30.43
30.35 30.31
30.35 30.1
30.35 30.21
30.35 30.57
30.35 30.3
30.35 30.37
30.35 30.67
30.35 30.32
30.35 30.46
30.35 30.73
30.35 30.36
30.35 30.64
30.35 30.63
30.35 30.49
30.35 30.66
30.35 30.68
30.35 30.44
30.35 30.26
Data set 2:
34.95 33.9
34.95 34.46
34.95 34.36
34.95 34
34.96 34.55
34.95 34.42
34.96 34.08
34.95 34.14
34.95 34.68
34.95 34.19
34.96 34.14
34.96 34.93
36.11 34.68
36.76 35.42
42.13 35.11
44.34 38.69
49.32 37.69
57.09 34.91
64.09 33.17
69.18 30.21
75.1 24.9
80.83 19.13
85.16 14.92
88.97 13.11
91.73 11.32
94.86 11.09
97.43 11.2
99.89 11.7
100 11.83
100 11.49
100 11.96
100 12.2
100 13.92
100 14.15
100 14.57
100 20.37
100 22.1
100 22.77
100 23.26
100 24.55
100 25.38
100 24.92
100 24.36
100 24.84
100 26.1
100 25.44
100 19.97
100 21.46
100 24.43
100 68.05
100 102.65
100 105.55
100 104.39
100 104.1
100 103.37
100 107.06
100 101.12
100 94.19
100 90.77
100 90.81
100 91.41
100 91.57
100 91.69
100 91.81
100 91.42
100 91.48
100 91.81
100 92.37
100 92.3
100 92.84
100 92.94
100 93.96
100 93.92
100 93.67
100 94.11
100 94.93
100 94.82
100 94.97
100 95.26
100 95.3
100 95.76
100 95.62
100 95.81
100 96.34
100 96.65
100 113.18
100 104.83
100 100.89
100 110.47
100 108.78
100 100.63
100 109.47
100 108.44
100 101.65
100 109.92
100 109.58
100 99.7
100 108.52
100 112.92
96.02 100.17
93.49 95.9
Data set 3:
34.96 34.74
34.96 34.92
34.95 34.83
34.96 34.77
34.96 35.06
34.96 35.11
36.14 35.14
36.63 35.4
37.17 36.06
40.08 35.92
43.05 36.53
52.64 40.58
58.77 50.51
65.47 61.44
69.89 66.03
76.88 70.65
83.75 78.6
89.05 85.83
92.9 89.77
97.68 94.87
100 99.27
100 100.9
100 98.56
100 98.23
100 100.18
100 101.79
100 103.68
100 103.35
100 105.82
100 105.6
100 104.49
100 105.61
100 112.21
100 114.93
100 91.86
100 97.83
100 97.96
100 98.96
My thought is that the engine is still in limp mode when the engine is up to operating temperature, so it behaves in the same manner as when there is an issue when the engine is cold. Once you clear the code with the engine warm, it’s no longer in limp mode, so the engine behaves normally.
(Also, just for my own understanding, the pressure data above is from the second and third blocks in group 140. Is the correct nomenclature for referring to these blocks 140,2 and 140,3 ? I could not access the Advanced Measuring Block feature in VCDS as it was greyed out. My understanding is this would let me simply check boxes for the data I wanted to record. Is there a way to access this feature?)
Your data would be better presented in a graph with an rpm and throttle opening or MAF reference.
I have had my share of temperature related issues and often enough they have been related to electrical connectors making poor contact. Do both of your fuel pump connectors fit snugly and lock into place?
Thanks, I’ll do that. Where can I find those values? The info on Ross-Tech doesn’t match up with S6 measuring block locations.
Will also disconnect and reconnect connectors.
Well, could not get the problem to occur yesterday or today so far…
Problem came back yesterday…
And, it’s BACK again…