RS2 rough idle and stupid 00561 code

[BosnianS2]

As the title says I am fighting these two problems now. Car has developed rough idle about 4 weeks ago, but I was limited with time to work on it until now.

Litte background, I replaced the O2 sensor Bosch, New PCV vale (Audi) ( old one broke apart during boost), new IC (Wagner) (old one was damaged by crankshaft pulley) and all small vacuum lines, new DV (Audi TTRS version N), new injector cups (Audi), new ICV (Bosch). I pressure tested the system and found some of the above items not good and therefore I replaced them.

I pressure tested the system again on sunday and I am finding very tiny leak at 1 bar pressure around injector cup 3 and 4. I thing i used wrong type of teflon tape to seal them so I will correct that however i dont think that that is a cause for my rough idle due to following reasons ( but I hope I am wrong):

Ecu throws this 00561 code after some drive. I cleared the code and found this interesting part: Engine idles fine first 10-15 sec after start, then you can hear at one point how idle changes from good to rough, almost as someone turns rough idle swicht on,

Then I follwed PRJs info and checked the group 000 and noticed that at poing where idle changes to rough this is same time when 2 sensor starts to oscilate. so here are photos when idle is fine from group 000 values and then after it gets rough idle:20150628_195551.jpg

20150628_195631.jpg

It seems also based on values 8 that ECU starts to add fuel (128 is base according to PRJ and greater value means ECU is adding fuel) and also value 2 should indicate MAF performance but I am not sure what is right.

Anybody has an idea?

[UrS4boy]

G70 Mass Air Flow (MAF) sensor info including cleaning, testing, etc

Sorry but anytime you bring prj into the question, it just means that we (the non-prjs) are very likely to be berated for whatever we say about the problem. At least that has been my experience. Ask prj directly.

All that said, since the 00561 code points at the MAF as one of the usual suspects and the MAF connection has proven to be a common source of various running issues, I suggest that you remove and clean and service the MAF connector, using hints provided in this G70 MAF info post:

http://forums.quattroworld.com/s4s6/msgs/20442.phtml

2413 (Blink Fault Code), 00561 VAG1551/2 Fault Code Number
Mixture Adjustment, Adaptation limit exceeded, Adaptation limit not reached, Leakage in exhaust system before 3 Way catalytic converters, Incorrect signal for Mass Air Flow Sensor, Spark plugs, ignition coil(s), or Ignition Coil Power output stage malfunctioning Symptom: Rich mixture, increased fuel consumption

[BosnianS2]

First of all thanks for the info and as far as this comment regarding PRJ and berating I dont want to comment as I dont have this experience. I appreciate anybodys input and take all serously because when I need help and aybody that takes time to try to help me out I know how to respect that. I just said that I followed PRJs info cause in all threads that I found that related to similar problem he made lot of input, that is all. So please dont take me wrong .

As far as this connector I already checked and cleaned and gave some contact spray treatment to pins. However what is really interesting is that rough idle starts at some point and not from start immediately. I suspect my self bad O2 sensor even though its a new Bosch part, but I am not sure so that is why I wrote here in hope that someone had something similar or can maybe based on group 000 values notice something.

What should be a normal value on idle Group 000 pos 2 for MAF?

[mike74]

Maybe worthwhile cleaning the MAF with alcohol to see if it helps any...it won't do any harm at least!
(just DO NOT touch the wires inside the MAF!)

[BosnianS2]

You mean sort of wash it out with alcohol?

[mike74]

Yip

[UrS4boy]

G70 Mass Air Flow (MAF) sensor info

You mean sort of wash it out with alcohol?

When I provide people with info links, I do so because there is information inside the posts that they need to read and learn, like cleaning your MAF.

I will try again:

G70 Mass Air Flow (MAF) sensor info
http://forums.quattroworld.com/s4s6/msgs/20442.phtml

[Error404]

You mean sort of wash it out with alcohol?

Gently use some 400g wet & dry followed by contact cleaner on the MAF connector terminals. I use dielectric grease on all my engine bay connectors to protect them.

I can also supply new gold plated terminals: http://www.s2forum.com/forum/showthr...ht=gold+plated

You can use a carb cleaner aerosol to clean the MAF wires.

HTH

[BosnianS2]

When I provide people with info links, I do so because there is information inside the posts that they need to read and learn, like cleaning your MAF.

I will try again:

G70 Mass Air Flow (MAF) sensor info
http://forums.quattroworld.com/s4s6/msgs/20442.phtml

I read this info that you posted but there is nothing there reagarding cleaning inside of MAF, it shows only pin issue, which I dont have. Mine are in very good shape and I cleaned them and sprayed with contact cleaner long time ago even though they looked good .

However I changed the O2 Sensor last Friday,even though one that was installed was only 2 Months old. I drow the car to thos Swiss Alps tour this weekend and made about 1500km, from which at least 500 were extremly hard driving up the Alps. I checked codes on saturday and sunday and the code 00561 never came back. It seems that i had a bad NEW O2 sensor.

I will keep my eyes on it and let you guys know if the problem is gone, but it was gone for at least this past weekend

[GT500]

It took me ages to find my 561. Turned out to be fuel pressure. Check it.

[BosnianS2]

It took me ages to find my 561. Turned out to be fuel pressure. Check it.

I measured the pressure last week and I get 4 bar at idle ( My guage was ebay special set so i dont trust it to be 100% accurate). Of course i can not tell what happens when i drive and engine makes boost, but at least value at Idle seem sto be ok. If i remove vacuum line from FPR it raises to about 4,5 bar, which should be also ok.

What was your issue? Low pressure under boost ?

[GT500]

I measured the pressure last week and I get 4 bar at idle ( My guage was ebay special set so i dont trust it to be 100% accurate). Of course i can not tell what happens when i drive and engine makes boost, but at least value at Idle seem sto be ok. If i remove vacuum line from FPR it raises to about 4,5 bar, which should be also ok.

What was your issue? Low pressure under boost ?

Mine being an rs2 it should be 4 bar but I seem to remember s2 should be 4.2 on idle. It should on the side of the regulator.

Hth

[UrS4boy]

20VT Fuel Pressure Regulator Info

Mine being an rs2 it should be 4 bar but I seem to remember s2 should be 4.2 on idle. It should on the side of the regulator.

Umm... no x 2.

RS2 fuel pressure regulators are 3.8 Bar. (AAN and ABY are 4 bar)

At idle the fuel pressure in the fuel rail will be 3.8 Bar *MINUS* engine vacuum.

20VT Fuel Pressure Regulator Info:

http://forums.quattroworld.com/s4s6/msgs/21108.phtml

[GT500]

My bad. It was ten years ago. To be 0.2 of a bar out. Tut tut.

Aren't folk from over the pond RUDE!!
Urmm... Prat.

[UrS4boy]

My bad. It was ten years ago. To be 0.2 of a bar out. Tut tut.
Aren't folk from over the pond RUDE!!

At least we can do math and understand how fuel pressure regulators work.

Fuel rail pressure = Rated FPR pressure plus boost (or minus vacuum).