RS4

B6/7 S4/RS4
#1

This thread is informational, I’m documenting my progress since information regarding misfires and fixes is scarce and different per member.

A little recap on the car and maintenance. Car has 104K miles, Carbon clean, JHM Spacers, JHM 6 Rib Kit, Heater bypass, new spark plugs, was done at 99K miles. And fuel filter was replaced at 103K miles.

Having an issue with the car now and don’t want to throw money, was thinking injectors but it might be a combination of things. this is a rough summary of todays events.

  1. Replaced Rear 02 Sensors with (2) new Bosch units for Emissions testings.
  2. Drove around a lot so the car could adapt since I didn’t know or could not find anything related to setting readiness on RS4’s
  3. 1 hr later car is ready for emissions testings
  4. Car is backed up onto emission service station ramps and within seconds falls on its face
  5. Tried starting the car, once car was level again and CEL popped on, pulled codes and got a code for N276 Malfunction.
  6. After car started we cleared the codes and drove it, no issues.
  7. Because of the codes we were going to have to drive around again to set readiness, but decided to Contact ROSS Tech instead with assistance on setting readiness manually.
  8. ROSS Tech on the phone guiding me through the steps for setting readiness, everything going well. Basic Setting (Value 71) Emission Reduction = PASS
  9. Next, Basic settings Value block (34) Lambda Control, with foot on the brake pedal, use other foot and press the accel pedal until 2K RPM and hold. (this is where the car acted up)
  10. Car is stuttering and misfiring while trying to set readiness with a flashing CEL, so we back off the throttle.
  11. Contacted Jimmy Bones for better VAGCOM assistance, and we were able to monitor misfires at idle and load.
  12. Don’t remember the block values but I was seeing constant misfires on cyl 5, 7, 8 with a count of like 300+ each cyl.
  13. Initial thinking is injectors, Jimmy performed a Carbon clean on my car 5k miles ago with new plugs, and other parts. (Fuel Filter was replaced 1 1/2 wks ago)
  14. thoughts?
#2

So I went into the garage today to start the car, rough misfire during the cold start but no CEL. took out the VAGCOM to log and drove down the street still no misfires. once car was warmed up CEL started flashing and I counted 300+ misfires on CYL 5, 7, 8.

Here’s my results from logging.


http://i1366.photobucket.com/albums/r764/VRS4Dog/Logs_zpscj3h1tio.png~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/Bank1%20Eng%2001_zpsvwldmi1x.png~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/Bank2%20EngII_zpsl1h2yixt.png~original

#3

Started the process of removing the injectors and sending them off to get cleaned and flow matched, also going to swap the coil packs to see if misfires follow to rule them out.

Also will add, it’s be roughly 4k miles since carbon cleaning and the valves already have black gook all over them. I assumed it would be a little bit cleaner.

I’ll post those pics later.

FYI, pulling the injectors was a pita, anyone have a good procedure for injector removal? I pried mine but didn’t feel comfortable applying so much force?

http://images.tapatalk-cdn.com/15/12/13/33af6f7dfd60ef3b2b519b4faf753ceb.jpg

#4

:UPADTE!!!

Quick recap, I was getting a crazy misfire count at idle on cyl 5, 7, and 8. 300+ every cycle, car drove fine, and during some testing before tearing the car down this would only happen when the engine was warm, no CEL or misfires on cold startup. It would only occur onc car got up to operating temps. So the decision was to take a look at the injectors.

After spraying the injectors with a little PB Blaster, I still had 3 that were seized. They eventually broke off and I took a chance and purchased (3) from Rockauto.com for $57.00 each These are not listed under RS4 but rather the R8.

There is only one physical difference I can tell, between the OEM Hitachi one I have and these. (top hole on ours has a plastic reducer grommet making the inlet hole smaller) I have comparison picture below. The Injector with the dirty brownish lower seals is the old injector (right side), and the injector with the clean white seals is the new one (left Side).


http://i1366.photobucket.com/albums/r764/VRS4Dog/image2%202_zpsnoufb7qj.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0424_zps1qm4b2e5.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0423_zpsfm4a6mdl.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0435_zpsemsdjfta.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0421_zps5sb8npun.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0420_zpscifvpzvr.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/image1%203_zpsixbczeln.jpg~original

I had all the Injectors sent out to Injector City to be cleaned and flow matched. When I got the injectors back they were nice and clean, and Injector City replaced all the bad seals. So if you have a place that replaces Seals do not buy them unless you need to.
I purchased a kit, because I need the Repair that includes the cage bracket. The seal kit was $30.00 each from FCP Euro.


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0433_zpsucxu3sdg.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0431_zpsvb6q3zwp.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0426_zpssfgcmsil.jpg~original

Put the brackets on the injectors and put everything back together.


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0438_zps2u7j65fy.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0448_zpsbcvrping.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0449_zpsgzsamjrf.jpg~original

Didn’t take any final completion pictures. But the car is back together, took a couple cycles to turn over but she did. I let her warm-up and took the car for a small test drive. Everything appears to be in running order, I had VCDS on logging misfires and I had none, so I drove the car back home and let her sit over night. The next morning same thing, I started her up and took a drive, everything was running fine with no misfires or hiccups even after getting up to temp 90C in VCDS. Did a couple of rips up to 7K no problem car performed well! It appears the cleaning of the Injectors worked.

Mind you I have dead VA tags and still need to pass emission testing. So I tried to go in a set readiness through VCDS as I had previously tried unsuccessfully.

Throttle Body Adaptation (Channel 60) = PASS
EVAP Test (Channel 70,71) = PASS
Secondary Air Injection Test Channel 77) = PASS

Oxygen Sensor Test = fail, Basic setting channel 34

For some reason again my car doesn’t like this, when bringing up the rpm’s the car starts to stumble and I get a flashing CEL. So I backed off. I’m going to just drive the car and let it set readiness on the Oxygen sensor on it’s own since everything else has already passed.

After trying to set readiness I went back to logging misfires and drove home, I think I had 5 misfires pop up on Cyl 5 but that’s it. Car still drives fine. I’ll report back later with any new findings and emissions status.


http://i1366.photobucket.com/albums/r764/VRS4Dog/image1%204_zpsuqy5m96l.jpg~original

#5

it should only take one or two drive cycles for the 02 sensors to pass. If the car stumbles check your LTFT values and see what its at. There is a good chance that you have a vac leak or something in your oil seperator or PCV system has an issue.

#6

Misfires gone? Win

Also don’t forget to post pictures of the carbon after 4k

#7

Ok, will look into this thanks!

#8

Def a Win on no misfires, and forgot to post those Carbon Pics.

Not the best but should show enough, there’s a little buildup in there.


http://i1366.photobucket.com/albums/r764/VRS4Dog/image1%205_zpsvu467sos.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/image2%203_zpsodndik1h.jpg~original


http://i1366.photobucket.com/albums/r764/VRS4Dog/DSC_0392_zpsdhljdmaw.jpg~original

#9

It’s funny ,bwcause I’m sure you expect it to still be shiny almost, and then to see that… It’s annoying as hell.

But, we have to remember that a little carbon is a non factor. A bunch of carbon is a minor factor. It’s not really the end of the world the way it is portrayed on many other sites. It’s definitely not a 25-40 hp problem. I’m of the opinion (after considerable standardized acceleration testing of multiple rs4s) that it’s about 10 hp.