MAF sensor possible issue - Help please

[cutes6]

Hi

I have read loads of threads on Maf sensors and readings, unfortunately I can't do a log although I have Vagcom lite due to a knackered battery on PC.

I have measured block 003 while stationary at 3,000 revs give or take a little and the reading is usually between 11 and 11.8 and if I have understood this right then this is not right it should be somewhere around 10.

I started looking at this whole issue as my fuel consumption seems to be getting worse.

These sensors are expensive so I bow to superior knowledge and would ask if this reading is too high and if it is would that lead to poor consumption.

I have checked all pipes and my boost readings are -25 at tick over and will boost to 12 quickly and hold around 10 so I think I am OK there and also I am not getting any codes relating to this on Vagcom.

I also sometimes have a slight hiccup on tick over again something that has started to happen recently.

are there any other readings I can take while stationary to check the maf sensor out ?

Any help would be greatly appreciated, thanks.

 

[ibizacupra]

air leaks most common cause..
what are your fuel trims on 032?

your maf check does'nt confirm its working properly.. just that its measuring "something"

90% of the 1.8t I see have leaks from under the inlet manifold and pcv system
look for smeggy oily covered pipes.. a leak will be close by

 

[cutes6]

I badger thanks for taking the time to reply, as you are a guru on here I am sure your are very busy.

Fuel trims 032 - just a little help, do I just run the car on tick over and report back with the readings ? or is it done at 3,000 revs.

 

[ibizacupra]

032 just look at them. If you have fault code reset recently that resets them to zero and it has to learn new values again.. If its not been fault code reset for a day or so of driving it should have adapted and learnt new values.. which will be shown in 032.

just post em up

 

[cutes6]

Hi Badger, right I have just been out and covered about 20 miles as I had reset the fault codes, this may not be enough of a drive but I did give it some and drive gently, any way the figures are

Box 1 -3.8
Box 2 - 1.6

So if my understanding is correct this is well within scope ?

I looked at block 03 at 3,000 revs again and it does read around 11.2 to 11.8 still.

If it is well within spec then great I might not have a problem with the Maf sensor but this does not explain the reduced MPG and slightly fluffy tick over.

Like a few on here I am starting to wonder what to look at next although I have to say it goes very well but it has just got very thirsty by I recon 3-4 mpg mmmm ?

As I say minus vacuum on tick over is around -25 and it gets to over 10psi in boost in second and third gear and holds at around 9-10 psi up to the red line so this led me to believe I cant have any serious holes in the pipes if any which I appreciate could be wrong of me ?

No fault codes other than a dodgy ignition switch all though everything works perfectly.

The joys of older technical cars eh ......

 

[ibizacupra]

I would be getting a smoke test done at this point to confirm leaks or not.

trims are tolerable..

if you log 002,115,118 in 3rd/4th wot you will see what max g/s airflow you get for that boost...

144~150g/s region is ball park std 180bhp airflow

coolant temp sensor reading ok? ecu report 90'c once warmed up? dash say the same?

 

[cutes6]

Hi Badger, thanks for your time again.

This morning I programmed the Heating unit to code 51 and watch both temp readings and they appear to be spot on, the heating unit reading was slightly behind the dash unit but I believe this is normal. Once they both got to 90c they stayed there even if I drove it hard or left it tick over for a while so I think both the temp sensor and the thermostat are OK.

Unfortunately doing a wide open throttle is not an option at the moment as the PC battery has completely failed so need to be connected to the mains

I live near Newcastle and I struggling to find anyone that can do a smoke test but will keep trying.

It's the Cupra r amk engine so I would be curious to see what the readings would be.

Looking as closely as I can then the pipes under the inlet manifold do seem a bit oily but dam how do you get in there to remove the original factory one fit clips on some of the larger pipes, I dont have big hands but unless I start taking bits off I am not sure how I can do this, I will have to have another look when it's daylight again tomorrow.

Thanks again for your help so far - am I correct in thinking that you don't think its the maf sensor ? even though it seems a high reading (whatever that implies )

 

[ibizacupra]

cupra r on std map would be 170-180g/s stock approx

 

[cutes6]

Well I managed to get a laptop to work and have taken some logs and to say the least I am very disappointed and it does confirm that my car seems to have lost its sparkle in performance

I am sorry that I have to copy and paste the results but I am hoping someone can decipher and help me understand what the issues might be, Badger asked me to read blocks 002, 115 and 118 which are below, any help would be greatly appreciated as this performance is poor for an AMk engine, I did several runs and all about the same the maximum g/s reading of 142 is very disheartening, cheers



Group A: '002 Group B: '118 Group C: '118
RPM Load Inj. On Time Mass Flow RPM Temperature Load Absolute Pres. RPM Temperature Load Absolute Pres.
TIME TIME TIME
Marker STAMP /min % ms g/s STAMP /min °C % mbar STAMP /min °C % mbar
0 2280 85.7 8.5 43.22 0.42 2360 18 95.3 1290 0.81 2480 18 78 1450
1.21 2600 120.3 12.58 66.14 1.61 2760 17 62 1700 2.03 2960 16 60 1770
2.52 3160 132.3 13.26 78.53 2.92 3320 15 58.8 1700 3.32 3520 15 59.2 1710
3.74 3680 133.1 13.26 92.47 4.14 3800 15 59.2 1750 4.54 4040 15 58.8 1720
4.94 4160 128.6 12.92 102.06 5.45 4360 15 60.4 1730 5.85 4520 16 60 1730
6.25 4680 131.6 13.94 116.33 6.64 4840 17 61.2 1770 7.04 5000 17 61.2 1750
7.46 5160 130.8 13.26 130.5 7.86 5280 18 61.6 1750 8.26 5440 18 62.7 1770
8.75 5600 133.8 13.94 142.58 9.17 5720 18 63.5 1760 9.57 5840 19 61.2 1850
9.97 5960 120.3 11.9 142.72 10.37 6080 20 57.6 1730 10.77 6160 21 59.2 1650
11.18 6240 121.8 11.56 141.75 11.68 6320 21 58.4 1760 12.08 6400 21 57.6 1740
12.47 6440 112.8 11.56 141.44 12.89 6400 22 0 1670 13.29 6280 21 0 1210
13.69 6160 14.3 0 15 14.09 6000 23 0 1080 14.49 5880 24 0 1060
14.89 5720 12.8 0 14.08 15.3 5560 24 0 1050 15.7 5440 24 0 1040
16.1 5280 12.8 0 13.11 16.5 5160 24 0 1030 16.9 5040 24 0 1020
19.73 4200 12.8 0 10.67 20.13 4160 24 0 1010 19.32 4280 24 0 1030
20.92 4120 66.9 6.46 56.19 21.32 4000 21 0 1300 20.53 4080 24 0 1060
22.14 3120 16.5 1.7 9.25 22.54 3040 21 0 1000 21.74 3600 21 0 1130
23.34 3080 78.9 7.48 47.19 23.75 3080 20 0 1300 22.94 3040 21 17.3 1150

 

[cutes6]

Hopefully I have managed to find a way of posting my image here fingers crossed

First Link



If this works it will help to see my logs as I do need some help in trying to understand the problem with high fuel consumption and very clearly a big underperformance in horsepower.

 

[cutes6]

I have found another log I also did but not all of the right blocks but might help in giving me some advice please