Laggy boost on TDI 150. Vag-Com logs included

[sockpuppet]

I started noticing a bit of hesitation when I'm low down in a gear and the car seems un-responsive when I accelerate. I have flexed the turbo vanes using vag-com in case they were sticking, but I'm wondering if I have a boost leak? I used to be able to do 45mph in fourth gear and accelerate to overtake and the car would fly, but now I have to drop down to 3rd to get anywhere, I also noticed in 2nd gear if I boot it the turbo takes a while to kick in and doesn't pull like it used too.

Here are the logs for block 11 3rd gear foot flat to the floor till 4400 rpm

Wednesday 20 August 2014 19:49:31
038 906 019 KG 1.9l R4 EDC 0000SG 5342

Group A: '011
Engine speed Spec. intake press. Actual intake press. D.cycle MAP
TIME 2850-3150 2300-2600 2200-2800 35-80%
MARKER STAMP /min %
0.01 2499 1944 2028 62.6
0.43 2583 1932 1980 62.6
0.93 2667 1944 1932 61.8
1.34 2730 1932 1908 62.2
1.82 2814 2496 1968 27.9
2.3 2961 2496 2568 73.7
2.75 3087 2496 2460 69.7
3.2 3213 2496 2352 68.5
3.68 3318 2496 2328 68.5
4.2 3444 2496 2352 69.3
4.65 3570 2496 2388 71.3
5.12 3654 2496 2424 72.1
5.58 3780 2496 2460 72.9
6.01 3885 2472 2508 75.3
6.41 3969 2460 2532 77.7
6.83 4074 2424 2556 79.7
7.29 4158 2388 2508 80.5
7.71 4263 2352 2460 80.5
8.12 4326 2328 2424 81.3
8.6 4410 2292 2388 81.3

 

[Dan FR]

Are you sure that was foot flat to the floor? Throughout the entire log shown above? Something strange going on there if so, as there is a large increase in requested boost at 2800rpm. Before this the boost (request & actual) is very low for a PD150.

The reason you are not going anywhere before that is that the car isnt trying to make any more boost, its doing exactly what the ecu is asking for.

Re-do the log, but start from 1500rpm or even lower in 3rd, turn the TCS off, and plant your foot all the way through to at least 4000rpm. Once you've done that, if the result is the same then additional logging will be needed

 

[sockpuppet]

I'm pretty sure my foot was flat to the floor, but I will give it another try tonight. Is there any other blocks I should log while Im at it?

 

[Dan FR]

Log just the boost for now, any other logs need to be run one at a time to keep the sample rate high enough to be useful.

 

[sockpuppet]

Foot flat to the floor in 3rd:

Group A: '011 Group B:
Engine speed Spec. intake press. Actual intake press. D.cycle MAP
TIME 2850-3150 2300-2600 2200-2800 35-80% TIME
MARKER STAMP /min % STAMP
0.36 1428 1164 1080 30.3
0.76 1428 1212 1116 24.7
1.21 1512 1908 1212 23.9
1.72 1575 1968 1476 29.9
2.14 1680 2112 1872 39
2.55 1806 2244 2220 51.4
2.97 1932 2352 2484 56.2
3.39 2079 2400 2688 65.7
3.8 2205 2448 2880 74.9
4.28 2352 2484 2484 59
4.71 2499 2496 2280 57.8
5.18 2646 2496 2376 60.6
5.61 2772 2496 2484 65.3
6.02 2940 2496 2532 67.3
6.47 3087 2496 2484 67.3
6.87 3192 2496 2472 68.1
7.27 3297 2496 2460 68.5
7.74 3444 2496 2460 69.7
8.19 3570 2496 2460 70.1
8.61 3696 2496 2460 71.3
9.06 3801 2484 2472 72.1
9.51 3927 2472 2508 74.1
9.91 4053 2436 2532 76.9
10.34 4158 2400 2532 78.9
10.87 4242 2340 2496 79.3

 

[Adam4D]

Can you post the actual csv file?

Might aswell run all the logs needed, so 003, 004, 008 and 011 as said all 1 at a time.

3rd gear, foot flat, 1500-4000rpm

Either upload log files here or email them over if needed

 

[Adam4D]

Never mind, for some reason the log doesn't show well on tapatalk.

Actuator looks a tad too long, shorten it till your n75 at 4000rpm is about 80-85%.

This will affect the turbos whole boost character so general driving will be much better

 

[sockpuppet]

It won't let me attach the csv files? I logged 03 last night and will try to do 004 and 008 today.

How do I shorten the actuator?

Thursday 21 August 2014 19:51:55
038 906 019 KG 1.9l R4 EDC 0000SG 5342

Group A: '003 Group B:
Engine speed MAF (specified) MAF (actual) EGR duty cycle
TIME 790-870 230-350 210-370 40-75% TIME
MARKER STAMP /min mg/R mg/R % STAMP
0 1386 680 646.8 4.8
0.4 1470 850 759.5 4.8
0.83 1554 850 916.3 4.8
1.26 1680 850 1033.9 4.8
1.71 1806 850 1131.9 4.8
2.13 1953 850 1195.6 4.8
2.59 2079 850 1249.5 4.8
3.02 2226 850 1249.5 4.8
3.47 2373 850 984.9 4.8
3.92 2520 850 1078 4.8
4.35 2646 850 1141.7 4.8
4.77 2793 850 1205.4 4.8
5.2 2940 850 1185.8 4.8
5.69 3066 850 1171.1 4.8
6.15 3213 850 1166.2 4.8
6.6 3339 850 1166.2 4.8
7.03 3465 850 1146.6 4.8
7.45 3570 850 1131.9 4.8
7.87 3675 850 1122.1 4.8
8.3 3780 850 1117.2 4.8
8.75 3906 850 1117.2 4.8
9.19 4032 850 1107.4 4.8
9.62 4116 850 1102.5 4.8
10.04 4074 850 563.5 4.8
10.47 4011 850 524.3 4.8
10.88 3927 850 504.7 4.8
11.28 3822 850 504.7 4.8
11.8 3738 850 504.7 4.8
12.24 3633 850 504.7 4.8
12.69 3528 580 499.8 4.8

 

[Dan FR]

Don't touch the actuator, it's fine. Hitting 79% DC @ 4200rpm with a tiny overboost is perfect. A percent or too will make no real difference, its when you start getting less than 70% at 4000rpm you really need to worry

What both logs are showing me though is that you have an overboost issue, spiking to nearly 1.9 BAR. As a result of this the ecu heavily pulls back for a second to bring the boost down. After that the log looks fine, MAF is reading plenty of airflow, 1100mg @ 4000rpm.

Nothing in the log indicates a boost leak, the VNT may be slow to react or not fully closing resulting in the laggy/slow to respond sensation but cant see that in a WOT run.

Have you checked the actuator & VNT mechanism are moving freely and through the whole range of movement that they should?

 

[Adam4D]

I always aim for 80% @4000rpm, it'll be half a turn on the actuator, plus it'll feel slightly less laggy accelerating overtaking etc.

 

[Dan FR]

If setting up a new turbo i would agree to aim for around that, but from what the OP said, no hardware changes were made and it was previously fine. 80% is about the most you want to hit fullstop, the final range of travel is there for boost control and overboost protection. 80% at 4000 rpm could be well over 85% closer to 4500-5000rpm. Adjusting the actuator would only attempt to mask the real problem.

Sockpuppet - when you say you flexed the turbo vanes, i assume you mean the block 11 test that raises rpm and cycles the actuator? if so did you look at the actuator movement and check it moved through its full range?

 

[Adam4D]

Could well need a new actuator, if you run with no undertray the water goes in them and rusts them out

Other options are blocked cat.

If your not getting it remapped shorten the rod half a turn.
If you are getting it remapped leave it alone the mapper will adjust it all

I do hope you haven't messed with the stop screw on a factory built turbo either sockpuppet

 

[sockpuppet]

You have now worries about me moving the stop screw or touching the actuator as I don't know where they are. The under tray is on the car and always has been.

I was sat in the car the whole time when I flexed the turbo vanes using vagcom so I don't know if the actuator goes full range, I will have to lookon elsawin to see where and what the actuator looks like.
I wonder if the vanes could be sticky as its on 180000 miles now, I don't know if it has any bearing on the state of the turbo, but the egr was replaced 18 months back and the old on had a couple of millimeters coating of gunk. The new one has no gunk but a bit of oil in there, is that normal?

 

[Dan FR]

If its the original turbo and it hasn't been changed then it won't need adjusting.

Actuator is difficult to see if you still have the EGR and cooler as its right at the back of the engine. After 180,000 i think you've been lucky not to experience issues until now and it is quite possible. Small amount of oil is normal and nothing to worry about

 

[sockpuppet]

Is it worth trying to get the turbo cleaned or just live with it and hope it lasts for another couple of years till I bin the car.

 

[Dan FR]

Cleaning it will help, should also reduce the overboost you have too, disabling the EGR might also be a good idea

 

[sockpuppet]

I got under the car over the weekend and if I tilted my head at the right angle I could see the actuator moving the bar up and down. I couldn't get anywhere near it to move it by hand or to even mark it to see how much movement the bar had (it looked like about an inch) and there was no rust on the bar or actuator that I could see.
I managed to log 004 and 008 blocks, but since then I have had an intermittent blowing sound out of the air filter box when the car is stationary and when the revs go down to idle. It seems to happen when first starting the car and I'm wondering if the n75 or n18 is playing up, would those valves cause the over boost and is there a way to measure them in vagcom?

Here are the logs:

Monday 1 September 2014 19:14:24
038 906 019 KG 1.9l R4 EDC 0000SG 5342

Group A: '004 Group B: Not Running Group C: Not Running
Engine speed Spec start of inj. Spec inj. duration Synchro. angle
TIME 790-870 4BTDC-2ATDC 3-8 °Ck. -3..+3°Ck. TIME TIME
MARKER STAMP /min °ATDC CF CF STAMP STAMP
0 903 1.2 5.6 -0.6
0.41 903 1.2 5.6 -1.1
0.84 903 1.2 5.6 -0.6
1.32 903 1.2 5.6 -0.6
1.79 903 1.2 5.6 -0.6
2.25 903 1.2 5.6 -1.1
2.68 903 1.2 5.6 -1.1
3.12 903 1.2 5.6 -0.6
3.58 903 1.2 5.6 -1.1
3.99 903 1.2 5.6 -0.6
4.45 903 1.2 5.6 -0.6
4.92 903 1.2 5.6 -1.1
5.37 903 1.2 5.6 -0.6
81.78 1575 10.9 13.8 -1.1
82.21 1701 11.5 17.3 -0.6
82.63 1806 11.8 18.4 -0.6
83.06 1932 12.1 19.4 -0.6
83.54 2079 12.4 19.4 -0.6
84 2226 13 19.9 -0.6
84.43 2373 13.6 20.4 0
84.86 2520 14.3 20.4 -0.6
85.31 2667 14.9 20.9 -0.6
85.74 2814 15.5 20.9 -1.1
86.23 2940 16.1 21.4 -1.1
86.69 3066 17.1 21.9 -1.1
87.14 3213 17.7 22.4 -1.7
87.62 3318 18.3 22.9 -1.7
88.06 3444 18.9 23.5 -2.2
88.48 3549 19.5 24 -1.1
88.91 3633 19.8 24.5 -0.6
89.37 3759 20.5 24.5 0
89.89 3864 21.1 25 1.1
90.38 3990 21.7 25.5 0
90.82 4116 22.3 25 0
91.21 4179 22.6 24.5 0
91.65 4263 22.9 24 0

Monday 1 September 2014 19:17:17
038 906 019 KG 1.9l R4 EDC 0000SG 5342

Group A: '008 Group B: Not Running Group C: Not Running
Engine speed IQ driver's req IQ via rpm(Torq) IQ via MAF
TIME 2850-3150 65-70 52-54 52-60 TIME TIME
MARKER STAMP /min mg/R mg/R mg/R STAMP STAMP
0 2205 24.4 55.5 34.6
0.4 2331 23.6 54.9 29.9
0.8 2436 26.1 54.6 26.9
1.26 2604 28.8 54.1 46.9
1.73 2583 0 54.1 46.1
2.21 2142 22 55.7 26.9
2.62 1869 69.7 56.8 55.2
3.07 2016 69.7 56.3 59.8
3.52 2163 69.7 55.7 59.6
3.92 2352 69.7 54.9 59
4.38 2499 69.7 54.4 58.2
4.83 2646 69.7 54.1 57.6
5.3 2835 69.7 53.8 57.1
5.74 2982 69.7 53.8 56.5
6.2 3129 69.7 53.8 56.3
6.6 3276 69.7 53.8 56.3
7 3381 69.7 53.8 56.3
7.53 3507 69.7 53.8 56.3
7.96 3675 69.7 53.8 56.3
8.41 3801 69.7 53.8 56.3
8.82 3927 69.7 53.8 56.3
9.23 4032 69.7 53.3 56.3
9.64 4158 69.2 51.1 56.3
10.09 4263 68.9 48.9 55.7
10.52 4347 68.4 46.4 53.3

 

[Adam4D]

Logs look fine apart from Cambelt sync is a little retarded at -1degree not that it will make it lack power tho.

Other suggestions are cam worn

Otherwise I'd say you have just a standard pd150 that looks ok via logs

 

[sockpuppet]

Thought I would update this as I found an intermittent camshaft position sensor fault. Changed the sensor (£47 from eurocarparts for the premium sensor) and this was a fairly straight forward job if you follow the instructions (https://www.youtube.com/watch?v=r4GzRBmhMO0). I jammed a large rag in and around the cambelt so if I dropped the bolt for the sensor it would drop onto the rag and not end up lost in the bottom of the engine somewhere.

This seems to have fixed my boost issues.