Beetle is sick... MAF? Fuel?

Luis

Veteran Member
Joined
Aug 23, 2000
Location
México City, D.F.
Hello people. Let's see if anyone here has had this same problem.

I have been suspecting my MAF is out of order because under high torque/power demand above 3,000 rpms you can feel a sudden (slight) loss of power as if the turbo suddently cut back its boost.

This was the only symptom until yesterday's morning...

I cranked up the car, waited a few seconds, moved the stick to Reverse, and as I was pulling out the clutch and started to request power from my engine it started misfiring as if it had no fuel. I pressed the gas pedal and it ran really nasty, lots of smoke. I drove off to work and noticed that the faulty behaviour occurs only in a specific throtle position....

Even at normal temperature, when driving at or around that specific throtle position, you can easily feel the uneven firing and a cloud of smoke out the exhaust.

I have added a double dose of Diesel Kleen to see if the fault goes away, thinking it might be a fuel/injectors related problem...

Whay do you people think about this ? Oh, and there is no CEL...

What are the symptoms of "air bubbles" in the fuel system ?

Luis
Y2K NB TDI (90 HP ALH engine)
 

NothernSky

Veteran Member
Joined
Feb 26, 2001
Location
Monterrey, Nuevo Leon MEXICO
TDI
Jetta, Model 2001, red
Luis, good to have a contry man around the forum (Monterrey NL)!!!


Do you have any mods on it?
I have the mods listed in my signature and it was doing that, but because of a bad connection bewteen the Tunning Box,EGR and the MAF.

Hope to hear from you soon!!!


P.D. It might do that at High Altitude ej, Saltillo, Cola de Caballo...etc.

[ November 09, 2001: Message edited by: NothernSky ]</p>
 

Curious Chris

Top Post Dawg
Joined
Jun 11, 2001
Location
Pineview GA
TDI
Jetta Wagon 2003 RIP Rockford IL
My first recommendation is to do a search at this site for "Who has VAG" and find someone near you who can plug into your car to eliminate many questions you have listed.

My car had your first stated symptom, ie no power above 3000 rpm, 100% throttle. Yup, it felt like the turbo just cut out. With the VAG tool plugged in and logging, nope not the turbo, its the MAF.

If you get a slugs of air into your pump the car will run like crap. But you can check for this by looking at the clear piece of poly tubing that goes from your fuel filter to the injection pump. If air is the problem you will see more air than fuel in that tubing; I am convince a few air bubbles is normal.

To make my response more complicated, you should check your snow screen for clogging, probably change your fuel filter as one tank of crap fuel can clog it....

But the VAG tool is the key to keeping your chasing of the problem to a minimum. Can you tell I love my VAG tool from RossTech.com!!
 

Luis

Veteran Member
Joined
Aug 23, 2000
Location
México City, D.F.
Ok, I got rid of the misfirings... A couple of weeks ago I had changed the fuel filter, so I decided to start looking there for the problem.

Apparently, I had left the filter "too high" on the mounting fixture. I loosened the screw a little bit, and lowered the filter all the way down. Retightened the screw, and voila!

No more misfirings... My conclusion: Air leakage through the t-connector. (?)...

Next step will be taking the car to a Stealership to be diagnosed for BAD MAF Syndrome and try to talk them into a no-cost "recall"...

Keep the good work!
Luis
 
Top