Checking MAF on a 2.0 Gasser?

[TurbineTech]

Can I use my VagCom to check the MAF on a '94 MK3 Jetta with a 2.0. My son was quite excited to learn that he did have an OBD port on his car and wants to know if I can do any tweeks on it. It seems to be underpowered and sucking a lot of gas.

Checked the Ross-tech website and it looks like it will work for the Engine checks, is the login code the same?

 

[Uwe]

Sure you can check the MAF. I believe the readings will be in grams/second rather than mg/stroke.

VAG-COM works fine on that motor, but there's no tweaks that I'm aware of. That's a fairly primive 8-bit ECU.

On that car, VAG-COM will also do:

* Airbags
* Auto Trans (if equipped)
* ABS (if equipped).

-Uwe-

 

[TurbineTech]

Any idea what values I should be looking for, and how I would know if the MAF is toast

 

[weedeater]

desired vs actual.

 

[Uwe]

The engine doesn't work on a "desired vs. actual" basis for mass airflow. Totally different algorithms than the TDIs. Best way is to run some logs at full throttle and compare to a known good car.

-Uwe-

 

[VelvetFoot]

I don't have the Bentley CD with me at the moment, but a while ago I tested my nephew's car, which did have a MAF-related MIL. I do recall a few open throttle, fairly high rpm runs. The difference wasn't super easy to see, except at those conditions. As I said the MIL was lit up and there was a MAF code. I put in my old spare 2.0 MAF in and the code did not come back. It really did not seem to drive that bad with the bad MAF.

What I got out of it was that the light comes on easier in the gasser than in the diesel. Maybe if the light is not on in your case, the MAF is not bad.

oops...just noticed - it's a 94. I take it back.

 

[TurbineTech]

So what's differant about the '94? Can the MAF be bad without throwing a light?

 

[VelvetFoot]

I just meant that I don't know. Someone who does know should chime in.

 

[TurbineTech]

Ok so here is what I got-it's all Greek to me...well not all

Engine/Measuring Blocks

001
RPM: 846/min
Temp:98.7 degrees C
Lambda Factor:1.01
Ign. Timing:-3.0

002
RPM:840/Min
Inj.On Time:4.10
Voltage:13.33
Temp:217.0 degrees C

003
RPM:840/Min
Load:2%
TB Angle:10.00
Temp:70.0 C

004
RPM:840/Min
Load:2%
Speed:0.0 Km/H
Bin Bits: 00010

005
RPM: 840/Min
Lambda Factor: 1.02
Load: 65%
Bin Bits: 0001

006
Lambda Factor: 0.98
Lambda Factor: 1.02
Lambda Factor: 1.00
Lambda Factor: 0.99

If anyone has any idea what all of this means, there's one Canadian nickle in it for you.

Seriously, any help would....help.

Could not see anything on the MAF

 

[Uwe]

OK, I was thinking '96-99 2.0, which has the same "ABA" code letters as the 93-95. Looks like the '93-95 does not have any direct MAF reading. However, if all your Lambda values are between .95 and 1.05, I think it's safe to assume that your MAF and 02 sensor are both happy.

-Uwe-