Boosting Issues - Now With Loggs (Post 19)

[Mat]

Ok, after a little help here......

When I first bought the Cupra, it used to boost to 25psi (well, 24-26) in every gear....

However, since about March time, it only pulls about 20psi. When I first noticed this, I wasn't too fussed. Also, a mate thought it may have something to do with high temperatures (as in weather)....

Anyway, recently it's been getting "worse" and slightly unpredictable....

So, I've been thinking about what I've "done" to the car....

Jan - Fitted FMIC
Feb - Fitted Cat Back Exhaust

Neither of those could/should cause any boosting issues.

Another thing was replacing the vacuum hose on the top of the DV in March because it split. Then I remembered that I've also blanked off the hole on the TIP where the PCV valve goes, with a locking wheel nut. Could this cause an issue? As it's like a hexagonal shape....

Anyway, I'm goin to try and blank that off with something else, and also change all the Vac Hoses from 4mm to new 3mm stuff. Hopefully, if it's a leak, I should find it.......

Sorry for rambling on...... anyway





Here's the weird bit, I was messing around a few weeks ago, and again last night (and every so often in between), and the boost seems to be different...

For example, last night I noticed it only boosted about 10psi in 2nd, then 15 in 3rd, 4th & 5th. Normally I don't pay attention to 2nd gear boost, but it caught my eye last night.

I usually pay attention to 3rd, 4th and 5th gear boost. Recently it seems to pull 15psi in 3rd and 4th, then change to 5th and get 20psi. Sometimes, I only get 15psi in 5th gear also. Sometimes I might get 18-20psi in 3rd, 4th & 5th. Like last night for example, all 3 gears pulled 15psi, slowed down at a junction, booted it again, then started pulling 20psi....

Now if it was a leak, I could understand a loss of boost, and say for example, ALWAYS running 15psi. What I don't understand is how one minute I'm getting 15psi, several minutes later, I might get 20psi or vise-versa....

What could cause this?

Oh, and let's not forget, it originally used to run 26psi, and I want to get that back again!

Help & Suggestions please

Mat

 

[Robbie C]

Time to get it on VAG COM once you've checked the obvious for boost leaks

Log actual vs requested boost, MAF readings etc and let's see what's going on

 

[Mat]

my laptop wi VAG COM on is ****ed, usually use my mates code reader and that doesn't pick up any codes!

 

[Mat]

could the N75 be causing the boost issue? Was wondering if it's more of an "electrical" fault rather than just a leak.... Obviously, I'll be checking for leaks first (next week hopefully). But how would i know if the N75 was faulty?

 

[s1l3nc3r]

Think its normaly N75 related if your bost is abit random...Would of thought a leak would of been consistant all the time.

Have you noticed any surging aswell..??

 

[Mat]

no not really. I have a feeling it's n75 related. Mate suggested sticky valve. Anyway, got all new hoese to put on next week, service kit for 007p DV and just need to borrow someone else's N75 to see if it runs better

Just asked manager to borrow hers, she said no (think she's worried hers wont work after, plus she has no idea what i'm talking about)

 

[daves ibiza]

i had this problem mate and turned out to be n75 nackerd . i no what id put my money on

 

[Mat]

indeed.... just wanna borrow someones just to be sure (don't wanna spend £60-£80 to find out its not causing the fault)

 

[PhilW]

How much? N75's can be found for about 30-40 quid.

 

[Mat]

Seen £30 on eBay for used.

Rather have a new

 

[daves ibiza]

i wouldnt buy second hand mate i have 2 duff ones here . havnt you got anyone near you to see if its n75 causing this

 

[Mat]

not i can think of... other than my manager, and she wont let me use hers! she said I can "look" at it, but not touch it!

stupid, slow, a4 convert driver!

 

[daves ibiza]

thats women for you mate

 

[Mat]

I've been advised my a member of staff from a tuning company (sponsers on here, mentioning no names), that a "race" valve, or anything other than standard would be a "waste of time". Reasoning behind it was that when it comes to being mapped in the future (hybrid or BT), then the "mapping company" will either map around the valve, or tell me to remove it....

So therefore, those running J valves, ECS etc (anything other than standard), is the uprated N75 actually doing anything extra than what the standard valve would since youhad it mapped? Something worth thinking about, and makes a bit of sense to me.

 

[daves ibiza]

did you get it sorted mate

 

[Mat]

not had chance yet, will be next week (working all week till 10pm), off from sunday until friday 4th december

 

[Mat]

ok, so I tried a mates N75 on Sunday, no difference at all. Only pulled 18-20psi. Time to change all hoses and hope for the best And hope to get Phil to run some logs at Cadwell on Friday

 

[Mat]

Managed to change all vacuum lines today and service DV. All lines have been changed from 4mm to 3mm.

Still not sorted boost issue out! Guess I'll have to get some logs run tomorrow at some point

 

[Mat]

Ran some loggs last wednesday, but they don't mean anything to me.... can anyone "de-cypher" them please

Also, had the EML code on saying "Manufacturer Control". Could this be related? (even though this boost issure has been goin on for some months and this is the first time I've had this code)

Anyway, here's the loggs (done in 2nd gear - not by me)

	RPM	Load	Absolute Pres.	Absolute Pres.
TIME				
STAMP	 /min	 %	 mbar	 mbar
0.33	840	14.3	980	980
0.63	840	14.3	980	980
0.92	840	13.5	980	980
1.23	840	14.3	980	980
1.59	840	13.5	980	980
1.98	840	13.5	980	980
2.32	840	13.5	980	980
2.62	840	14.3	980	980
2.92	760	17.3	980	980
3.22	800	18	980	980
3.52	800	18	980	980
3.92	800	19.5	980	980
4.22	840	18.8	980	980
4.52	840	18	980	980
4.82	800	18	980	980
5.12	800	19.5	980	980
5.42	800	20.3	980	980
5.72	840	19.5	980	980
6.02	840	19.5	980	980
6.33	840	19.5	980	980
6.62	840	20.3	980	980
6.92	800	21.1	980	980
7.22	800	21.1	980	980
7.52	800	21.1	980	980
7.82	800	22.6	980	980
8.12	840	23.3	980	980
8.52	920	21.1	980	980
8.82	880	15	980	980
9.12	880	20.3	980	980
9.43	800	18.8	980	980
9.72	880	18.8	980	980
10.02	920	15	980	990
10.32	840	12	980	980
10.63	840	16.5	980	980
11.02	800	15.8	980	980
11.32	720	21.8	980	980
11.72	1000	26.3	980	980
12.02	920	13.5	980	990
12.32	760	21.1	980	980
12.62	1000	37.6	980	980
12.92	1200	28.6	980	990
13.23	1400	33.1	980	980
13.52	1680	43.6	980	990
13.82	1800	45.9	980	1000
14.12	1720	44.4	980	1020
14.42	1520	40.6	980	1020
14.73	1320	36.8	980	1020
15.02	1080	37.6	980	1010
15.32	1080	37.6	980	1010
15.62	1160	33.8	980	1000
15.92	1280	33.8	980	1000
16.23	1400	34.6	980	1000
16.52	1520	37.6	980	1000
16.83	1640	39.1	980	1000
17.12	1680	30.8	980	1010
17.41	1680	12	980	1010
17.72	1360	10.5	980	1000
18.03	1160	12.8	980	990
18.32	1000	27.8	980	990
18.62	1000	20.3	980	990
18.92	1000	15.8	980	990
19.22	1000	13.5	980	990
19.52	960	10.5	980	990
19.82	920	9.8	980	990
20.11	920	8.3	980	990
20.42	880	9	980	980
20.72	880	9.8	980	980
21.02	880	9.8	980	980
21.32	880	12	980	980
21.62	840	13.5	980	980
21.92	840	12.8	980	980
22.21	840	11.3	980	980
22.51	800	11.3	980	980
22.81	800	12	980	980
23.13	800	17.3	980	980
23.41	760	21.8	980	980
23.72	760	26.3	980	980
24.01	760	26.3	980	980
24.32	760	28.6	980	980
24.63	800	52.6	980	980
24.92	840	53.4	980	990
25.21	880	47.4	980	990
25.51	840	37.6	980	1000
25.81	840	19.5	980	990
26.12	840	16.5	980	990
26.41	840	16.5	980	990
26.72	880	15	980	990
27.01	840	15	980	990
27.31	800	23.3	980	980
27.61	800	24.8	980	980
27.92	800	27.1	980	980
28.21	800	26.3	980	980
28.51	800	30.1	980	980
28.81	840	42.1	980	980
29.12	880	42.9	980	990
29.41	880	41.4	980	990
29.71	920	39.8	980	990
30.02	920	38.3	980	990
30.41	960	37.6	980	990
30.71	960	36.1	980	990
31.01	1000	41.4	980	990
31.31	1040	48.1	980	990
31.62	1080	42.9	980	1000
31.91	1080	38.3	980	1000
32.21	1120	36.1	980	1000
32.51	1200	55.6	980	990
32.81	1240	66.9	1100	1010
33.11	1360	69.9	1080	1030
33.41	1440	72.9	1050	1060
33.73	1520	75.9	1050	1080
34.01	1600	79.7	1080	1110
34.31	1760	81.2	1070	1150
34.61	1840	83.5	1340	1170
34.91	1960	89.5	1380	1200
35.21	2120	98.5	1980	1250
35.51	2280	106.8	2060	1330
35.81	2480	115.8	2230	1430
36.13	2640	124.1	2380	1540
36.51	2880	135.3	2500	1690
36.81	3080	145.1	2500	1800
37.12	3360	156.4	2450	1930
37.41	3600	162.4	2390	2010
37.71	3840	166.9	2360	2070
38.01	4120	167.7	2300	2070
38.32	4320	163.9	2260	2050
38.64	4120	65.4	980	2210
39.02	4280	15	980	1210
39.31	4000	6.8	980	1100
39.61	3680	6.8	980	1060
39.9	3320	9	980	1040
40.21	3000	9.8	980	1030
40.51	2680	9.8	980	1020
40.8	2360	9.8	980	1020
41.11	2040	9.8	980	1010
41.41	1680	9.8	980	1010
41.71	1360	9.8	980	1010
42.01	1240	11.3	980	1000
42.31	1080	13.5	980	990
42.6	1000	14.3	980	990
42.91	920	15	980	990
43.21	840	16.5	980	990
43.53	840	17.3	980	990
43.91	880	16.5	980	990
44.2	880	15.8	980	990
44.5	840	15.8	980	990
44.81	840	15	980	990
45.11	840	15	980	980
45.4	840	15.8	980	980
45.71	840	15	980	980
46	840	14.3	980	980
46.31	840	15	980	980
46.6	840	14.3	980	980
46.9	800	12.8	980	980
47.3	840	29.3	980	980
47.6	1240	27.1	980	980
47.9	1480	29.3	980	980
48.2	1760	36.8	980	980
48.51	1840	37.6	980	990
48.8	1800	38.3	980	1000
49.1	1720	39.1	980	1010
49.4	1440	36.1	980	1020
49.71	1120	33.1	980	1010
50	880	38.3	980	1000
50.31	960	27.1	980	1000
50.6	960	16.5	980	1000
50.9	920	20.3	980	990
51.2	920	15	980	990
51.5	840	17.3	980	990
51.81	960	16.5	980	990
52.2	880	12.8	980	990
52.5	960	15.8	980	990
52.8	1200	24.8	980	980
53.1	1680	47.4	980	970
53.4	2760	68.4	980	1000
53.7	3320	66.9	980	1210
54	2760	38.3	980	1160
54.3	2320	35.3	980	1090
54.6	1920	33.1	980	1060
54.9	1520	32.3	980	1040
55.2	1200	37.6	980	1020
55.5	1360	46.6	980	1020
55.8	1560	60.9	980	1020
56.1	1800	72.9	1170	1050
56.4	2120	80.5	1380	1100
56.7	2480	96.2	1510	1180
57	2880	110.5	1590	1340
57.3	3360	129.3	1270	1590
57.61	3280	39.1	980	1590
58.01	3120	13.5	980	1140
58.3	2760	8.3	980	1070
58.6	2360	8.3	980	1040
58.9	2000	7.5	980	1030
59.2	1640	8.3	980	1010
59.49	1360	9.8	980	1010
59.8	1240	11.3	980	1000
60.09	1160	11.3	980	990
60.4	1080	12.8	980	990
60.69	1000	12	980	990
61.01	920	12.8	980	990
61.39	880	12	980	990
61.7	840	12	980	990
61.99	880	13.5	980	990
62.3	840	11.3	980	990
62.6	840	12.8	980	980
62.9	840	12.8	980	980
63.2	840	11.3	980	980
63.51	840	12	980	980
63.79	800	12.8	980	980
64.1	800	13.5	980	980
64.39	800	14.3	980	980
64.71	800	13.5	980	980
65	840	14.3	980	980
65.36	840	13.5	980	980
65.69	880	13.5	980	980
66.01	840	12	980	980
66.29	840	12.8	980	980
66.59	840	12	980	980
66.9	800	12.8	980	980
67.19	840	13.5	980	980
67.49	840	13.5	980	980
67.8	840	13.5	980	980
68.09	840	13.5	980	980
68.4	840	13.5	980	980
68.69	880	12.8	980	980
68.99	840	12	980	980
69.29	840	12.8	980	980
69.59	840	12	980	980
69.89	840	12	980	980
70.19	720	16.5	980	980
70.49	760	34.6	980	980
70.89	1200	15.8	980	990
71.19	1080	12.8	980	990
71.49	1040	14.3	980	990
71.79	1000	9	980	990
72.09	920	14.3	980	980
72.39	920	9.8	980	990
72.69	840	13.5	980	980
72.99	880	12	980	980
73.29	840	10.5	980	980
73.59	840	12	980	980
73.89	840	11.3	980	980
74.19	840	12	980	980
74.49	840	12	980	980
74.79	840	11.3	980	980
75.1	840	12	980	980
75.4	840	12	980	980
75.69	840	12	980	980
75.99	840	12	980	980
76.29	840	12	980	980
76.59	840	12	980	980
76.89	840	12	980	980
77.19	840	12	980	980
77.49	840	12	980	980
77.79	840	12	980	980
78.09	840	12	980	980
78.39	840	12	980	980
78.69	840	12	980	980
78.99	840	12	980	980
79.29	840	12	980	980
79.6	840	12	980	980
79.89	840	12	980	980
80.19	840	12.8	980	980
80.48	840	12	980	980
80.79	840	12	980	980
81.09	840	12	980	980
81.49	840	12	980	980
81.89	840	12	980	980

I'm guessing the most important bit is this part:

30.02	920	38.3	980	990
30.41	960	37.6	980	990
30.71	960	36.1	980	990
31.01	1000	41.4	980	990
31.31	1040	48.1	980	990
31.62	1080	42.9	980	1000
31.91	1080	38.3	980	1000
32.21	1120	36.1	980	1000
32.51	1200	55.6	980	990
32.81	1240	66.9	1100	1010
33.11	1360	69.9	1080	1030
33.41	1440	72.9	1050	1060
33.73	1520	75.9	1050	1080
34.01	1600	79.7	1080	1110
34.31	1760	81.2	1070	1150
34.61	1840	83.5	1340	1170
34.91	1960	89.5	1380	1200
35.21	2120	98.5	1980	1250
35.51	2280	106.8	2060	1330
35.81	2480	115.8	2230	1430
36.13	2640	124.1	2380	1540
36.51	2880	135.3	2500	1690
36.81	3080	145.1	2500	1800
37.12	3360	156.4	2450	1930
37.41	3600	162.4	2390	2010
37.71	3840	166.9	2360	2070
38.01	4120	167.7	2300	2070
38.32	4320	163.9	2260	2050
38.64	4120	65.4	980	2210
39.02	4280	15	980	1210
39.31	4000	6.8	980	1100
39.61	3680	6.8	980	1060
39.9	3320	9	980	1040
40.21	3000	9.8	980	1030
40.51	2680	9.8	980	1020
40.8	2360	9.8	980	1020
41.11	2040	9.8	980	1010
41.41	1680	9.8	980	1010
41.71	1360	9.8	980	1010
42.01	1240	11.3	980	1000
42.31	1080	13.5	980	990
42.6	1000	14.3	980	990
42.91	920	15	980	990
43.21	840	16.5	980	990
43.53	840	17.3	980	990

And I made a nice pretty graph for that range

Not sure if we ran the loggs on the correct black, as gavinchappel is only used to DERV logging

 

[Damoegan]

Have you done a boost leak test, Mat?

Next time you post logs just copy and past all the info from excel and add the code tags, just makes it easyer to read mate.

Try logging blocks 115 & 118.