jbka6

Could use some advise on this one...my 98 A-6 2.8 has a peculiar low rpm (under load) hesitation, only noticed while engine is warm and normally in reverse. The situation is most commonly replicated after driving (warm engine), then parking in my driveway for a few minutes, then backing uphill to leave. Engine hesitates around 1000-1400. Gunning it will blast thru hesitation, but lunge onto road which makes the neighbors and my self nervous.

Coincedentally or not, after replacing the (recall) fuel sending unit, engine ran poorly. Took back immediately to dealer and they swapped a #6 fuel injector and spark plug from diagnostic check. Now I am told there is a difference between "old" style injectors and "new" style--old style are no longer made. One dealer tells me the remaining 5 injector should be replaced while the other says that according to Audi, this is not necessary.

So...
1. Seems like a fuel isse. Ran Techtron thru no help. Perhaps a professional injector cleaning?
2. How significant is the "old" style fuel injector vs. "new". I hate to spend $400 needlessly.
3. Could replacement fuel sending unit (recall item) have anything to do with situation?
4. What else? Problem only occurs warm engine so some type of sensor?

Appreciate any insights since both dealers are having trouble with diagnosis.

dentman

do you have a vag comm to measure MAss air flow? does the studder go away once on the road and air is flowing over engine/cold air intake ?

JeTT 180QC

Mine does the same thing, but I've just ignored it as everything I've read indicates the shifting profile for this car is not sporty, and a chip upgrade might help. I'd be curious to see how your problem is resolved...

jbka6

No vag comm. Yes, studder goes away once driving forward. I found an interesting article about the MAF sensor on the tech link, engine section, of this site by Choy Ngee Hoe in 2000. He recommends wrapping the sensor with thick cloth to insulate from heat which apparently causes too lean a mixture in very hot climates (similar to mine). Interesting idea...thoughts?

dentman

Its a bandaid, I think that was authored before it was commonly known that the MY 2000 had bad bosch maf sensors. I think you need to get it on a vag comm, measure block 003 which will show rpm and mass air flow measured in grams per second. if you run in the 5500-6000 rpm range thru second and third gear and your maf doesnt hit 210 215 g/s, you've definately got a bad one.

I spent like a month toiling over the same problem and AW member singletrack helped me out alot with it.


I live in Pittsburgh, PA if your in the area, Id offer to help out. Otherwise if your going to do any level of self diagnosis, just buy the vag comm, they run 200 plus tax and shipping, its WELL worth the jing. Theres gobbs of other stuff you can play with. email me if you have any more questions

jbka6

otherwise I'll purchase and try what you suggest. Thanks again for the info. Hope this works.

Sebastian Costin

Have you found a solution for this issue?