Slowly failing MAF?

[Craig!]

I have noticed the car surges through the rev's on a cold start and have noticed is that my top speed is slightly down, so I belive the MAF is failing. After all it is the same MAF after 72,000 miles!!

After a quick maf run it seems to be ok it's pulling 150g/s however it did used to pull 158-161g/s at the same revvs with the same outside air temp. Can the MAF slowly fail like that, or will it normally go down in much higher rates?

So far there has been no signal to low errors, but I think it's just a matter of time!

 

[Simon L]

My MAF rate varies, sometimes its 155g/s, others its 145g/s, sometimes its in between.

I would only think its failing if its signifigantly lower than usual.

 

[Martyn]

Clean ya air filter and remember that during the cooler evenings the g/s reading is likely to be higher due to the density of the air.

*edit* Might be worth giving the MAF element a clean too.

 

[Colin]

Craig

The MAF was replaced by messer so it is probably only just 12 months old if that. I think u worry to much

 

[Radek]

How do you test MAF ?
Which blocks do you read from VAG ?

 

[Radek]

anybody ?

 

[Martyn]

Block 002, use 4th gear and run from 2.5k to 6.5k flat out (full throttle).

 

[Forbez]

Pissin vag vom, wont allow me to read blocks!

I'm starting to hate this car! With a vengence!
Nothings ever straight forward! (ever)

 

[Radek]

Martyn , what g/s values should I expect ?

 

[Martyn]

Depends on what car you own and if it has any mods mate

 

[Radek]

Ibiza Cupra 2001 , stock engine , intake pipe upgrade + N75(J) from Audi S2

 

[Martyn]

Anywhere from 110-130 g/s

 

[Radek]

I've done some tests few days ago :

,,RPM,Load,Inj. On Time,Mass Flow,,RPM,Mass Flow,Load,Ign. Timing,,,,,

,34.84,1520,69.9,9.84,22.94,35.14,1600,25.81,100.0,12.0,,,,,
,35.44,1680,82.0,10.25,28.67,35.74,1760,31.00,100.0,9.0,,,,,
,36.04,1800,91.7,11.48,34.64,36.34,1880,37.56,99.6,6.0,,,,,
,36.64,1960,101.5,12.71,39.61,36.94,2040,43.14,100.0,6.0,,,,,
,37.24,2160,110.5,13.94,45.94,37.54,2240,46.83,100.0,6.8,,,,,
,37.84,2320,110.5,13.94,48.72,38.14,2440,50.11,100.0,9.8,,,,,
,38.44,2520,109.0,13.94,51.19,38.74,2600,53.75,100.0,11.3,,,,,
,39.14,2720,106.8,13.53,56.86,39.44,2840,59.19,100.0,12.8,,,,,
,39.73,2920,109.0,13.53,61.78,40.03,3000,65.17,100.0,13.5,,,,,
,40.34,3120,110.5,13.94,66.08,40.65,3160,67.44,100.0,13.5,,,,,
,40.93,3280,109.8,13.94,69.31,41.24,3360,71.58,100.0,12.0,,,,,
,41.55,3480,109.0,13.94,73.25,41.84,3440,31.89,7.8,12.0,,,,,


Looks like it's 25.81 - 71.58 between 1520-3480 RPM
That's bad , isn't it ?

 

[Martyn]

You stopped at 3480 mate, it needs to go to 6k really.

 

[Radek]

Trafiic , you know
Will hit the red line in the evening and post the results

 

[Martyn]

Good stuff, post up the results when you have a 2.5k to 6k run

 

[Radek]

OK , got it ! 3-rd gear run , not possible to run on 4-th unfortunately

Sunday,21,May,2006,19:22:27
6K0 906 032 AQ ,,1.8l 20VT EU2       0001,

,Group A:,'002,,,,Group B:, Not Running,,,,Group C:, Not Running
,,RPM,Load,Inj. On Time,Mass Flow,,,,,,,,,,
,TIME,,,,,TIME,,,,,TIME,,,,
MARKER,STAMP, /min,%, ms, g/s,STAMP,,,,,STAMP,,,,
,0.29,2240,74.4,10.25,37.19,,,,,,,,,,
,0.59,2280,88.0,11.07,41.53,,,,,,,,,,
,0.89,2320,96.2,12.30,46.31,,,,,,,,,,
,1.19,2400,102.3,12.71,49.50,,,,,,,,,,
,1.49,2520,105.3,13.53,51.39,,,,,,,,,,
,1.79,2600,106.8,13.53,53.25,,,,,,,,,,
,2.09,2720,106.8,13.53,53.89,,,,,,,,,,
,2.40,2800,106.8,13.53,57.83,,,,,,,,,,
,2.69,2920,108.3,13.53,60.03,,,,,,,,,,
,3.10,3000,109.8,13.53,64.42,,,,,,,,,,
,3.40,3120,109.8,13.53,66.61,,,,,,,,,,
,3.69,3200,109.0,13.94,66.39,,,,,,,,,,
,3.99,3320,109.8,13.94,69.89,,,,,,,,,,
,4.38,3440,109.0,13.94,70.44,,,,,,,,,,
,4.69,3520,107.5,13.53,72.56,,,,,,,,,,
,4.98,3600,106.0,13.12,72.17,,,,,,,,,,
,5.28,3720,106.8,13.53,75.56,,,,,,,,,,
,5.59,3800,106.8,13.53,77.56,,,,,,,,,,
,5.89,3880,106.8,13.53,79.47,,,,,,,,,,
,6.19,3960,106.0,13.12,82.08,,,,,,,,,,
,6.49,4080,106.8,13.53,84.19,,,,,,,,,,
,6.79,4160,108.3,13.94,86.17,,,,,,,,,,
,7.09,4240,109.0,13.94,90.50,,,,,,,,,,
,7.39,4360,109.8,14.35,92.61,,,,,,,,,,
,7.79,4440,112.8,15.17,96.86,,,,,,,,,,
,8.09,4560,112.8,14.76,99.36,,,,,,,,,,
,8.39,4640,112.8,15.17,99.64,,,,,,,,,,
,8.69,4720,112.0,15.17,101.72,,,,,,,,,,
,9.09,4840,112.0,15.17,103.89,,,,,,,,,,
,9.39,4920,112.8,15.99,106.72,,,,,,,,,,
,9.69,5000,111.3,15.17,108.78,,,,,,,,,,
,9.99,5080,111.3,15.58,108.94,,,,,,,,,,
,10.29,5200,110.5,15.99,110.83,,,,,,,,,,
,10.59,5280,109.0,16.40,109.94,,,,,,,,,,
,10.89,5360,109.0,16.40,112.36,,,,,,,,,,
,11.19,5400,107.5,16.40,112.28,,,,,,,,,,
,11.49,5480,106.0,16.40,112.94,,,,,,,,,,
,11.79,5560,106.0,16.40,113.58,,,,,,,,,,
,12.09,5640,105.3,16.40,115.47,,,,,,,,,,
,12.39,5720,105.3,16.81,115.19,,,,,,,,,,
,12.69,5800,105.3,16.40,117.42,,,,,,,,,,
,12.99,5840,105.3,16.40,117.83,,,,,,,,,,
,13.29,5960,104.5,16.40,120.14,,,,,,,,,,
,13.59,6000,106.0,16.40,120.78,,,,,,,,,,
,13.89,6080,104.5,16.40,122.47,,,,,,,,,,
,14.19,6160,105.3,16.81,123.33,,,,,,,,,,
,14.49,6200,103.0,16.40,119.72,,,,,,,,,,
,14.79,6240,95.5,14.35,113.81,,,,,,,,,,
,15.11,6280,97.0,15.17,117.83,,,,,,,,,,

But I'm afraid my DV is leaking Can hear that
2-nd gear run

Sunday,21,May,2006,19:31:18
6K0 906 032 AQ ,,1.8l 20VT EU2       0001,

,Group A:,'115,,,,Group B:,'118,,,,Group C:, Not Running
,,RPM,Load,Absolute Pres.,Absolute Pres.,,RPM,Temperature,Load,Absolute Pres.,,,,,
,TIME,,,,,TIME,,,,,TIME,,,,
MARKER,STAMP, /min,%, mbar, mbar,STAMP, /min,°C,%, mbar,STAMP,,,,
,0.29,2320,75.9,1490.0,1060.0,0.59,2440,27.0,54.5,1190.0,,,,,
,0.89,2600,94.7,1520.0,1330.0,1.19,2800,27.0,45.5,1430.0,,,,,
,1.49,3000,107.5,1510.0,1490.0,1.79,3240,26.0,45.5,1520.0,,,,,
,2.10,3440,110.5,1480.0,1530.0,2.50,3800,25.0,42.7,1500.0,,,,,
,2.80,4000,106.0,1490.0,1490.0,3.10,4120,25.0,45.5,1480.0,,,,,
,3.49,4480,110.5,1460.0,1490.0,3.89,4760,26.0,50.6,1500.0,,,,,
,4.19,4960,112.0,1470.0,1490.0,4.49,5160,27.0,52.2,1480.0,,,,,
,4.80,5360,108.3,1490.0,1490.0,5.09,5560,29.0,54.1,1480.0,,,,,
,5.39,5760,104.5,1500.0,1470.0,5.69,5920,30.0,58.0,1460.0,,,,,
,5.99,6120,103.0,1420.0,1450.0,6.29,6280,32.0,61.2,1440.0,,,,,
,6.59,6440,99.2,1370.0,1450.0,6.89,6600,33.0,25.1,1440.0,,,,,
,7.19,6400,19.5,990.0,1420.0,7.49,5720,33.0,0.0,1210.0,,,,,

Wot do you think ?

 

[Martyn]

Boost looks ok to be honest mate, MAF does looks ok providing your car is standard.

 

[Radek]

How to double check boost leak ?
I hear it from inside the car . And sound like quiet WRC blow off valve when changing gears :O
I have standard plastic DV

 

[Jonzy]

Sounds like its died, forge 007p or another OE valve.