?? why can't I get a response BAD MAF conditions with brand new MAF

Jetta4Dollars · Feb 16, 2014

??Need HELP! why can't I get a response BAD MAF conditions with brand new MAF

Jetta 2003 243k miles. Owned since 129K, cleaned intake at 150K changed group 03 to reduce intake clogging. Installed Bosio PP520’s about 175k, replaced timing belt, accessories, and vacuum lines at 200k. The problem started about 10k ago, I have low power from 3k RPM and above. I have replaced the MAF with new Bosch from IDparts and the problem did not change. I have changed the N75 relay, MAP sensor and neither made any difference. I have verified the turbo vanes move with might Vac , the rod starts moving at 3lbs and continues to about 15-18 lbs. The car generates 25-28 lbs of vacuum at idle, mighty vac gauge I haven’t checked it while driving. I have recorded group 003 while under load in 3rd gear from 2800 RPM until 4000 RPM and the specified MAF is steady at 850 while the actual is bouncing around as the car pulses. The actual will briefly touch 950 at 2800 when I first hit 100% throttle then drops off to 650 max all the down to 430 while holding the throttle at 100%

IndigoBlueWagon · Feb 16, 2014

Intake may need cleaning again. If it's plugged enough to restrict airflow you'll get a low mass air flow reading because the air can't get through, not because the MAF is faulty. The change in group 03 helps but doesn't stop exhaust gasses from getting into the intake.

You may also have a split boost hose. The 90 degree hose that goes into the EGR on my car was split on the inside, couldn't see it when the hose was in place. That would affect power, but not MAF readings.

You might want to run boost logs. Re-reading your post I wonder if you're getting limp mode for some reason.

Jetta4Dollars · Feb 16, 2014

Thanks for your response, it doesn't go into limp mode.

IndigoBlueWagon · Feb 17, 2014

So when you see 430 max flow at 100% throttle you're seeing 14 PSI boost? Hmmm.

Here's another thought: plugged CAT. I had one in a '97 Jetta I bought and it wouldn't make power, even after tuning. Removing the cat fixed it.

CoolAirVw · Feb 17, 2014

There's lots of things that can cause lack of power other than what you've dealt with. Car I just worked on had the pin broken on the computer that turns on the 109 relay, so someone had installed a switch and jumpered 12V to the stop soleonid. This powered the computer "through the back door". the thing ran but lacked power like in limp mode or bad MAF.

I've had some other weird issues like voltage to the maf "falling" out. ect.

jetta 97 · Feb 17, 2014

Do the log of the MBV 011 , turbo boost and see what is going on.
If the boost in not close as specified then you may have clogging EGR and it is not closing all the way.

Dimitri16V · Feb 17, 2014

IndigoBlueWagon said:
Intake may need cleaning again. If it's plugged enough to restrict airflow you'll get a low mass air flow reading because the air can't get through, not because the MAF is faulty. The change in group 03 helps but doesn't stop exhaust gasses from getting into the intake.

You may also have a split boost hose. The 90 degree hose that goes into the EGR on my car was split on the inside, couldn't see it when the hose was in place. That would affect power, but not MAF readings.

You might want to run boost logs. Re-reading your post I wonder if you're getting limp mode for some reason.

what he said

If the actual reads a lot higher than specified and power is low , air is not making it in the engine

Metalhead · Feb 17, 2014

So the specified is higher than actual? That means air is making its way into the intake that isn't metered. I bet your N18 is bad, the solenoid which controls the vacuum that makes its way to the EGR valve. This would cause MORE exhaust to get pulled into the intake, which reduces the amount of air being pulled in through the MAF. Results in lower actual than specified MAF readings. But yours seems sporadic, I guess it's possible for an N18 to fail in a sporadic way... I bet you can get a used one for cheap, I got one for a friend for like 20 bucks shipped if I remember correctly.

How low on power is it? I doubt strongly this would cause a major loss in power.

Also replace vacuum lines, not sure if yours are new or not, but that always helps.

A5INKY · Feb 18, 2014

Logging MAF actual against MAP actual can be telling in situations like this. If you graph those values against RPM they should track together in a healthy engine. If MAP is maintaining but MAF is dropping off as I think you are trying to describe, that would point to an airflow restriction as IBW suggested, clogged intake, intake ports, cat.

Jetta4Dollars · Feb 19, 2014

Thanks for all the Reponses, Jetta 97 I ran 011 and this is the result
Boost Specified mbar 1948.2 Boost Actual mbar1448.4

It stays this way varying only a couple tenths for 30 seconds. I wish I could post the picture of the log but the website is not allowing me to post.

Jetta4Dollars · Feb 19, 2014

Thanks for all the responses, Jetta 97 I ran 011 the boost specified stayed at 1948.2 the boost actual was at 1448.4 it varied only by 10 mbar the specified didn't change.

A5INKY · Feb 19, 2014

That is but one data point. An under boosting data point for sure, but not nearly enough info. You will get much more help if you search how to log data with VCDS and post up the whole log.

Simultaneous logs of groups 3 (MAF/EGR),8 (IQ Limitation) & 11 (boost control) in 3rd gear WOT from 1800 RPM to redline would be helpful to see.

jetta 97 · Feb 20, 2014

Here is the how to make a LOG:
http://www.ross-tech.com/vcds/tour/logging.html

Also you need to have Microsoft Excel install in PC.

pmicaza · Feb 21, 2014

Hi,
You guys sound a lot more advanced than i am, but that never slowed me down...maybe turbo? even if the actuator moves, the vanes maybe worn, loose, bad?! when i had a similar situation, i remove/plugged all vacuum (not the brakes ) except the actuator to eliminate bad bits, leaky hoses, connectors etc. i also clamped the vent from the n75 (? The control device for the actuator ). this verifyed the actuator, vanes, intercooler piping and not clogged cat.

I didnt see that you cleaned the snow and air filters

It took me a long time to figure out i had multiple organ failure, n75 & maf, i had replaces each with no change so i put the old one back, lesson learned. i also (unnecesarily ) replaced the turbo so i you want a used one (160k) with a new actuator, lemme know.

BobnOH · Feb 21, 2014

What are the active and stored engine codes? None?

Jetta4Dollars · Feb 21, 2014

The car has good power up to 3K and sometimes it pulls hard to a higher RPM, then it just goes flat and starts surging. There are no codes stored or active. With power pulling to 3k or higher sometimes is there still a possibility of the Cat?
I will run another log tomorrow with 3, 8 & 11 as A5INKY suggested
This one is with 003 & 010
http://pics.tdiclub.com/data/uploads//86061/Group_03_ALH_feb14.PNG

40X40 · Feb 21, 2014

Does the car smoke when it acts up? Have you changed the fuel filter?

Bill

Jetta4Dollars · Feb 21, 2014

New fuel filter, air filter, clean snow screen. The car doesn't smoke any more than normal, it always smokes a little when my foots on the mat.

jetta 97 · Feb 21, 2014

Something reducing your Air flow after 3000 prm.
I need to see other log with group 011, so I can tell you what possible can be your problem.

Jetta4Dollars · Feb 22, 2014

Jetta, 97 I was planning on running a new log this morning. A5 suggested 03, 08, & 11 would this give you the information you need or do you want a different group?

Jetta4Dollars · Feb 22, 2014

Log 03,10,11
http://pics.tdiclub.com/data/uploads//86061/LOG-01-003-010-011.xlsx

Jetta4Dollars · Feb 22, 2014

log 03,08,11
http://pics.tdiclub.com/data/uploads//86061/LOG-01-003-008-011.xlsx

jetta 97 · Feb 22, 2014

I would say check your intake .
Boost looks OK , not best but OK,But I would say MAF is your only problem .
It is really strange why MAF going down after 3000 rpm.

Jetta4Dollars · Feb 23, 2014

I was doubtful but you guys nailed it!!!

The intake was cleaned at 150K and I made the (off Road) adjustment to reduce EGR gases. Now at 243K the intake looks really bad. I will send it out to NAPA and have them tank it for me. It should be reinstalled next weekend after I order up the gaskets and bolt kit from IDParts. Thanks for all the input and suggestions.

http://pics.tdiclub.com/data/uploads//86061/photo_429.JPG

IndigoBlueWagon · Feb 23, 2014

Yikes. Cleaning that will help. Funny how it's the simple things sometimes.

A5INKY · Feb 23, 2014

Glad you figured it out.

Wankel7 · Feb 23, 2014

Jetta4Dollars said:
I will send it out to NAPA and have them tank it for me.

Interesting, what do they charge?

jetta 97 · Feb 24, 2014

Jetta4Dollars said:
The intake was cleaned at 150K and I made the (off Road) adjustment to reduce EGR gases. Now at 243K the intake looks really bad. I will send it out to NAPA and have them tank it for me. It should be reinstalled next weekend after I order up the gaskets and bolt kit from IDParts. Thanks for all the input and suggestions.

http://pics.tdiclub.com/data/uploads//86061/photo_429.JPG

Problem with intake is driving conditions.
If you do not drive TDi aggressive, intake will have problem always.
I clean my intake 100k ago and when I check it, it was clean.
But I do not shift under 3500-4000 rpm and gas pedal in always in floor

.
But,
however I know some people does not fill driving like that I think best way is to delete EGR in ECU for people who does not drive like me.
If you interested in this you can PM me.

Jetta4Dollars · Feb 24, 2014

NAPA intake cleaning

Wankel7 said:
Interesting, what do they charge?

The last time I has them do it was $20 cash.

Wankel7 · Feb 24, 2014

Jetta4Dollars said:
The last time I has them do it was $20 cash.

About what I spent on buying a tupperware tub and chemicals...I will have to check out my local NAPA.

?? why can't I get a response BAD MAF conditions with brand new MAF

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