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Cristisor
12-09-2010, 12:07 AM
Hi guys. I am new on this forum and I want to say hello to everyone here.
I am facing a problem with my MAF, at least the guy that checked it says so. I see that I can't upload any files here, so I will just put some values from the log, maybe someone can tell me if it's working ok or not

First log:
Engine Speed Injection Period Injection Period Intake Air Mass

11.67 2520 3.2 6.02 16.94
11.93 2640 3.05 5.76 17.01
12.19 2760 2.95 5.93 17.01
12.45 2880 2.85 5.5 17.22
12.71 3000 2.7 5.16 17.01
12.97 3120 2.6 5.16 17.08
13.23 3200 2.6 5.07 17.5
13.5 3320 2.7 5.16 19.86
13.76 3480 3.45 6.71 25.42
14.02 3600 3.6 6.88 27.5
14.28 3760 3.65 6.88 28.68
14.55 3920 3.55 6.71 29.03
14.8 4080 3.45 6.62 29.58
15.07 4240 3.35 6.71 29.58
15.33 4360 3.3 6.11 30.07
15.6 4480 3.2 6.28 30.21
15.85 4600 3.15 6.02 30.21
16.11 4760 3.05 5.76 30.62
16.38 4840 3.05 5.93 30.83
16.64 4960 2.95 5.5 30.83
16.9 5040 2.9 5.59 30.62
17.16 5120 2.85 4.9 29.37

Second log:
Engine Speed Injection Period Injection Period Intake Air Mass
88.31 2840 3.95 7.48 23.89
88.57 2960 3.9 7.31 23.61
88.84 2760 4.05 7.4 24.58
89.1 2840 3.95 7.22 23.96
89.36 2880 3.85 7.4 23.4
89.62 2920 3.8 7.14 23.96
89.89 2960 3.85 7.05 23.75
90.15 2960 3.9 7.48 24.17
90.44 2960 3.95 7.31 24.72
90.69 3000 4 7.4 25.48
90.95 3080 6 12.13 41.94
91.21 3160 6.25 11.44 41.46
91.48 3240 6.15 11.7 42.08
91.73 3360 6.15 11.61 42.98
91.99 3440 6.3 11.27 45.34
92.25 3560 6.4 11.95 47.92
92.52 3640 6.5 12.73 50.28
92.78 3720 6.5 12.3 51.53
93.03 3800 6.4 11.44 51.18
93.3 3880 6.4 12.38 52.78
93.56 4000 6.35 12.04 52.84

I think that the Intake Air Mass should grow as the Speed grows, but on the first log it's around 30 at 5000 rpm and on the second one it's around 50 at 4000 RPM.
Isn't this strange?
The car is an Audi B5 made in '96, 1.6 ADP engine.
Thank you.

Cristisor
12-09-2010, 10:14 PM
Nobody knows how to read a MAF log? :(

biketsai
12-09-2010, 10:22 PM
Are you doing this in 3rd gear? You usually need to do a WOT

Cristisor
12-10-2010, 03:40 AM
Yes, I did it in the 3rd gear I think. What is a WOT?

frameshift18
12-10-2010, 03:42 AM
Wide Open Throttle. Foot to the floor. You want to log while taking it up to around 6000rpm.

Cristisor
12-10-2010, 03:44 AM
The log was created up to 5000, not 6000. But there are some anomalies. If you can give me your email address, I can send you the full log in xls format, I am sure that it will be easier to read.
Thanks a lot for answering.

Cristisor
12-13-2010, 10:40 PM
Still waiting for some opinions :(

biketsai
12-13-2010, 11:15 PM
email me, biketsai@yahoo

ricekikr
12-14-2010, 12:12 AM
Log block 003. Press the throttle to the floor from around 1500rpm to any RPM that concerns you. This will give you a better picture of whats going on.

But the best is to log 003 from 1000rpm to redline. The throttle should be pegged to the floor. WOT = Wide Open Throttle.

Cristisor
12-14-2010, 02:57 AM
Ricekikr I already did this, if you read my first post you will see. But I can't upload my log here on the forum so I posted only some values. But if you can help me with this, I can email you the full log and you can analyze it on your computer. The log is in Microsoft Excel format, xls.
Biketsay I emailed you the log at biketsai@yahoo.com. Looking forward for your reply. Thanks.

ricekikr
12-14-2010, 03:41 AM
I just noticed you had a 1.6. I'm not too familiar with that engine. I don't have any data to compare it with.

Some generic info though. Check for vacuum leaks or dirty maf. Either can cause low/erratic Maf reading.

If your idle is perfect. I'd check if the maf is dirty first. If idle is crappy, I'd check for vacuum leaks.

*I assume the logs you posted were done @WOT.

Cristisor
12-14-2010, 04:27 AM
Ricekikr the logs were don @WOT.

The MAF and the acceleration pedal have been cleaned, but my idle is not perfect :( the vacuum leaks look ok, I checked all of them.

What else can cause the crappy idle? The MAF can do this?

ricekikr
12-14-2010, 06:13 AM
Acceleration pedal? If you cleaned your MAF already, it could be busted already.

How did you check for leaks? If your 1.6 is somewhat similar to a 1.8t, there will be tons of hoses/valves hidden from sight. Worse yet is the cracks can be so thin/small that they're unnoticeable.


Rough idle can be caused by a lot of reasons.
Vacuum leak
Idle control valve
MAF
Dirty throttle body
Spark plugs
Coils
Bad gas
Compression loss
etc etc etc

One question, is the car running fine except for the "not perfect" / "crappy" idle and erratic maf reading?

*Again not familiar with your engine. I doubt anyone here is. This forum is mostly for cars/engines available in the US/CA.

Cristisor
12-14-2010, 12:22 PM
Unfortunately the 1.6 engine is not very common over there because you have high power engines, but gas is very very expensive here and we can't afford to buy such big engines.

I made a mistake, I was talking about the throttle body and I said "acceleration pedal".

So the throttle body and the MAF have been cleaned buy someone that did this many times before and this guy also checked my vacuum leaks and he didn't notice any problems.
You are right, there are a lot of causes for the rough idle, and I would have to change half of the car in order to find my problem.

Except the crappy idle I don't have any problems with the car, the engine runs ok, I don't loose power when I accelerate. I will make one more test by removing the MAF connector, and if the idle will be ok, then this might be my problem.

Thanks a lot for your help!

Cristisor
02-23-2011, 12:23 AM
After a long period of searching I finally found the answer to my problem. The condition is to do a full-throttle run all the way to redline in a single gear (second works fine). Group 002 usually shows air mass in g/s. The peak airflow should be roughly 0.80 times the horsepower. So, if the stock is 150 hp 1.8T, expect around 120 g/s. If the value is significantly less than that, the MAF may be on the way out.

M-Hood
02-23-2011, 11:06 AM
If the .8 works then I guess my K03 was actually making almost 270hp since I was hitting 215 g/s :)


I cant remember but is it block 002 that gives the engine load readings or is that block 003? It always helps to figure out of the MAF is on its way out.

somebody5788
02-23-2011, 11:23 AM
If the .8 works then I guess my K03 was actually making almost 270hp since I was hitting 215 g/s :)


I cant remember but is it block 002 that gives the engine load readings or is that block 003? It always helps to figure out of the MAF is on its way out.

That can't be correct to calculate that. I'm pulling like 290 or more

M-Hood
02-23-2011, 12:06 PM
That can't be correct to calculate that. I'm pulling like 290 or more

So you dont feel your making 360hp at the crank or about 280awhp?

The .8 info is from Rosstech.


Odd thing is that most Xchip 2001 A4 1.8t's get around 175 g/s which comes out to 218.75 chp.

somebody5788
02-23-2011, 12:16 PM
So you dont feel your making 360hp at the crank or about 280awhp?

The .8 info is from Rosstech.


Odd thing is that most Xchip 2001 A4 1.8t's get around 175 g/s which comes out to 218.75 chp.

Not even remotely close lol. I wish! And I'm doing that air flow at 6 psi

M-Hood
02-23-2011, 12:29 PM
Maybe its different for a 2.8 maf reading. Are you still running stock sensor/housing?

somebody5788
02-23-2011, 01:01 PM
Maybe its different for a 2.8 maf reading. Are you still running stock sensor/housing?

Ya stock 3" MAF.

Cristisor
02-24-2011, 04:21 AM
Yes, I got .8 from Ross-Tech and on my 101 HP I got 83 g/s, so I think that it's correct. If you ask why my car only has 101 HP then I have to tell you that the gas here is much more expensive and the wages are lower.