Running rough when cold, and occasionally running really rich

[FWP!]

Since it's gotten a lot cooler here in Phoenix, I've noticed a few things.

One - when I first start up the car in the morning, I'll let it idle for 15-20 seconds, back out of my garage, and when I first get going in 1st and then 2nd gear, the car bucks and spits and runs terribly when I try to even very lightly accelerate, then about 1 minute after I've started it, it goes back to normal, nothing's wrong, runs and drives perfectly.

Two - Occasionally (maybe once a day) once the car is hot, if it is idling for a while (at a stop light, or a drive thru for example), if I blip the throttle at all while I'm just sitting there, the car will PUUUUUUUUUUKE super rich, dark exhaust smoke. It smells and looks like an old boat starting up and there is a huge cloud of smoke. It looks terrible. It is NOT oil, I thought it was maybe my PCV system getting plugged up, but it's absolutely extremely rich exhaust. I have have had this going on for about two months now, and about two months ago is when I ran a bottle of Seafoam through the tank. Then about a month ago one of my HPFP's died so I replaced them both with the updated models, thought that might have fixed it because I didn't see it for a while, but it just did it yesterday while I was at a light.

I'm starting to wonder if I have a "sticky" injector, it is as if the car is DUMPING fuel into the cylinders almost uncontrollably. Other thought I had was a bad fuel pressure regulator, but I have 0 codes in VAG COM related to it, just ones for my rear O2 sensors (I have 4 new ones ready to get installed). I would love to log what is going on, but it happens so randomly that I'd have to be logging ALL the time to catch it.

Main mods to the engine - JHM 91 tune, JHM intake spacers, de-catted Milltek downpipes, JHM throttle body coolant bypass mod. I installed new plugs and a fuel filter earlier this year, new crank angle sensor in July, and the valves didn't look too bad the last time I had the IM off over the summer to do the spacers. I was hoping to see something with VAG COM codes, but it just doesn't like my rear O2's. The times it BELCHES that smoke randomly after it's been idling for a while looks awful and I'd really like to figure out what it is. Any input is appreciated!

[Jake@JHM]

No codes?

We have seen injectors fail before, so it is possible.

[quattro16]

How many miles? Needs carbon cleaning and might as well put injectors in it too. Will run like a champ after....

[wednesday]

Thinking out loud: what about a rupture or hairline crack in one of the vacuum lines? While hairline cracks usually do not create clouds of smoke, but it could be. Do you also have a rough idle when this happens?

[FWP!]

No codes?

We have seen injectors fail before, so it is possible.

Just rear O2's. Says the right one is too slow to warm up, and the left one is not responding sometimes.

How many miles? Needs carbon cleaning and might as well put injectors in it too. Will run like a champ after....

87k, did a CC around 20k miles ago.

Thinking out loud: what about a rupture or hairline crack in one of the vacuum lines? While hairline cracks usually do not create clouds of smoke, but it could be. Do you also have a rough idle when this happens?

Are you saying the crack could mess with vacuum readings in the intake manifold, throwing off fuel pressure?

[Jake@JHM]

Bad o2 sesnors can cause fuel trim issues. I would try replacing them and seeing how the car responds

[wednesday]

Just rear O2's. Says the right one is too slow to warm up, and the left one is not responding sometimes.



87k, did a CC around 20k miles ago.



Are you saying the crack could mess with vacuum readings in the intake manifold, throwing off fuel pressure?

Vacuum readings - yes. Fuel pressure - no.

[wednesday]

Bad o2 sesnors can cause fuel trim issues. I would try replacing them and seeing how the car responds

For testing purposes, could this be "faked" - O2 spacers maybe?

[Quattrors4]

It's very easy to check ,engine ,basic setting,
106 and run test on both banks
If test fail it's vaccum or fuel issue

[komseh]

One of the symptoms I had prior to cleaning my fuel injectors was rough running @ cold start. It was acting exactly as you described.

[FWP!]

Bad o2 sesnors can cause fuel trim issues. I would try replacing them and seeing how the car responds

Yea, I need to get those installed. I was waiting to get some replacement cats welded in to the downpipes so I could do it all at the same time.

Vacuum readings - yes. Fuel pressure - no.

Gotcha.. I'll check it out.

It's very easy to check ,engine ,basic setting,
106 and run test on both banks
If test fail it's vaccum or fuel issue

Thanks, I'll look at this today.

One of the symptoms I had prior to cleaning my fuel injectors was rough running @ cold start. It was acting exactly as you described.

Interesting.. and it does seem to have happened after I replaced the fuel filter and dumped in a bottle of Seafoam into the tank. Maybe it flushed some trash up to the injectors and now they're clogged.

[OscarMeyer]

One of the symptoms I had prior to cleaning my fuel injectors was rough running @ cold start. It was acting exactly as you described.

I have the same issue, haven't gotten the injectors over to be cleaned as of yet, damn garage build.

Quick question fwp, your last thread you created you mentioned you had pinging, did you ever get that resolved? Or is this still a lingering issue? I ask cause I have almost identical symptoms as you on cold starts, but I don't have any rich smoke as I just replaced my 02's, but I have yet to actually find the cause(my belief is an irregular flowing/spraying injector/injectors.)

I feel like you may also have a similar issue? I know you changed just about everything else, have you tried injectors yet? Komseh has a great thread on checking your injectors over on revolution, it may be here as well, but have you checked your long term fuel trims?

[musanoadsaba]

OscarMeyer, are you sending your injectors to those injector guys in Kelowna?

[OscarMeyer]

BD Diesel, although they don't have it listed they use an asnu machine. Plus the bonus is they are 5 Min's from my house.

[FWP!]

I have the same issue, haven't gotten the injectors over to be cleaned as of yet, damn garage build.

Quick question fwp, your last thread you created you mentioned you had pinging, did you ever get that resolved? Or is this still a lingering issue? I ask cause I have almost identical symptoms as you on cold starts, but I don't have any rich smoke as I just replaced my 02's, but I have yet to actually find the cause(my belief is an irregular flowing/spraying injector/injectors.)

I feel like you may also have a similar issue? I know you changed just about everything else, have you tried injectors yet? Komseh has a great thread on checking your injectors over on revolution, it may be here as well, but have you checked your long term fuel trims?

I haven't done the injectors yet, but I'm thinking now about getting mine sent out to get cleaned. I still have pinging on throttle tip-in between gears at high RPM's, it's only a split second that I can hear it, but it's definitely there.

How should I check my long term fuel trims?

[OscarMeyer]

The pinging I experienced is exactly as you put it, tip in, tip out of gear changes and quick throttle acceleration. Now when I logged my long term fuel trims, they were alittle out of wack, but nothing that others were experiencing ie:komseh

Here is the fuel injector maintenance, my information was posted on revolution, but like usual I can link that thread.
http://www.audizine.com/forum/showthread.php?t=675100

[FWP!]

The pinging I experienced is exactly as you put it, tip in, tip out of gear changes and quick throttle acceleration. Now when I logged my long term fuel trims, they were alittle out of wack, but nothing that others were experiencing ie:komseh

Here is the fuel injector maintenance, my information was posted on revolution, but like usual I can link that thread.
http://www.audizine.com/forum/showthread.php?t=675100

Fuel trims look OK. I installed 4 new O2 sensors today, I'll see if that helps and report back in a few days.

[OscarMeyer]

Ya definitely see how the 02's do, like I said my fuel trims where alittle off, but still within spec.

Jimmybones has thread on revolution about doing work on customer cars, on one car he was doing he was having sputtering and other issues, he performed a carbon clean, pcv, and a few other things and also pulled the injectors, I remember him posting shots of the injector faces, and pretty sure the one that looked as if it was in decent shape was the one causing issues.

[highPSI-S4]

Along with the issue today that I posted in the injector maintenance thread, I also have had rough cold start misfires since last winter. I figured carbon Clean was the issue, however carbon clean was done and i'm still having rough idle cold start misfires. Will look into this as well. I will log and report back.

[AWD Addict]

FWP were you able to figure out what's causing the toxic cloud? I'm having, what sounds like, the exact same problem.

[FWP!]

FWP were you able to figure out what's causing the toxic cloud? I'm having, what sounds like, the exact same problem.

To be determined...

I have tried to see if modifying the PCV system would help any. I have basically gone from 4cm of crankcase vacuum to around 15cm by modifying an internal restrictor in the PCV valve. The thought is that it will help oil from getting pushed by the valve seals.

What's strange is before it used to smoke every time after idling for a while and then touching the gas. Now it's only doing it about once a week if I drive the car every day. Doesn't smoke at startup, doesn't smoke at all until randomly I'll be sitting at a light, take off, and I get the huge cloud of smoke coming out of both tailpipes.

I'm going to do a compression and leakdown test soon, I'm curious if my rings got screwed up running on the terrible JHM tune last summer. If it's compression, then it's time for a new motor.

[AWD Addict]

So your car doesn't push out a cloud of exhaust when you start it up in the morning?


Sent from my iPhone using Tapatalk

[FWP!]

So your car doesn't push out a cloud of exhaust when you start it up in the morning?


Sent from my iPhone using Tapatalk

No, it doesn't anymore since I went to a new PCV. And trust me, I watch my mirrors every single time I start it up in the morning, I just haven't seen it do it in a long time.

[B6_Dolphin]

Long shot, but my cold start misfires were due to the factory calibration and running with gasoline + E10. I got the flash update at the dealer, and then got my EPL Tune, since the TSB would have over-written the tune. Depending on your 2007 VIN, it may or may not be in the applicable range.

Date: December 20, 2010
To: All Audi Dealers, General Managers, Service Managers, Sales Managers, Parts Managers and Warranty Administrators
From: Audi Product Compliance
Subject: Required Vehicle Update 24T9

Model Year 2007 - 2008 Audi RS4 and RS4 Cabriolet

ECM Software Update for Cold Start


This communication is to inform you of Required Vehicle Update (RVU) 24T9.

What vehicles are affected?

There are 1,208 Model Year 2007 - 2008 Audi vehicles affected in the U.S. by this RVU.

What is the issue?

On certain Audi RS4 and RS4 Cabriolet vehicles manufactured within a specific period it is possible that the engine runs rough (misfires) after cold start.

What does the repair procedure involve?

ECM software update.

When will the Required Vehicle Update technical bulletin be available?

RVU 24T9 will be visible in ElsaWeb and ServiceNet on or about December 21, 2010.



Please refer to the ElsaWeb campaign/action screen for confirmation of whether the update applies to each specific vehicle. Additionally, RVU Technical Bulletin 24T9 is posted on ElsaWeb and ServiceNet for additional information and complete repair instructions.



Consistent with general Audi corporate policy governing Required Vehicle Updates, Audi is not notifying consumers. (RVUs differ from recalls and service actions; consumers are notified in writing of recalls and service actions.) Each vehicle should be completed when it is in to the dealer for maintenance or any other service visit. Dealer stock vehicles cannot, however, be delivered to consumers until the RVU is completed.



To identify any vehicles in your inventory that are affected by this RVU, please run the "New Vehicle Inventory Open Campaign/Action Listing" report from the AIM system.

Please ensure that every affected vehicle gets the update before delivery to consumers. Your effort is integral in reaching the highest quality expectations of Audi customers.


Thank you for your cooperation and assistance in this important matter.

Here are the important tidbits from the TSB:


Technical Service Bulletin
RVU 24T9 - RS 4 ECM update cold start misfire
24 10 58 2025168/1.

Model(s) Year VIN Range Vehicle-Specific Equipment
RS 4 2007 907201 - 999999
RS 4 2008 900000 - 999999
RS 4 Cabrio 2008 800000 - 999999
4.2 FSI


Condition
This RVU has been proactively released to prevent the following condition from occurring in the vehicle:
MIL on.
DTC stored.
Engine runs rough (misfires) after cold start.
The following DTCs are logged in the memory of the ECM: DTC P0300 - P0308 (misfire).
This condition will not cause stalling or drivability concerns.

This Required Vehicle Update (RVU) is in effect until September 12th, 2014. After that date, this RVU will expire and no longer be in effect.
Vehicle must meet all of the following criteria:
Procedure is valid only for vehicles that show the 24T9 code in the ElsaWeb Campaign/Action Information screen on the day of repair.
Vehicle must be within the Federal Emissions Warranty period.
Procedure must be performed within the allotted time frame stated in this Technical Service Bulletin.
Procedure must be performed on applicable vehicles in dealer inventory prior to sale.

Technical Background

Over the last 3 years the capability of fuel available in the United States to evaporate at low temperatures (~32-80°F) has decreased, while still being within the tolerance band of EPA specification.
Initial engine calibration was based on worst case fuel blend at the time.
Some 2007 and 2008 RS4 engines are more sensitive to changes in evaporative behavior of fuel.

Also the variation in Ethanol content (0-10%) influences the engine calibration requirements. In order to adjust to the shift in the evaporative behavior of available fuel, the engine control software was updated.

Service

1. If you encounter a vehicle with a tuned ECM or TCM, your dealership must do the following before performing any procedure that updates ECM or TCM programming:
Note:
Any Update Programming procedure (flash) may overwrite any tuned ECM or TCM programming. A tuned ECM or TCM is described as any ECM or TCM altered so as to perform outside the normal parameters and specifications approved by Audi of America, Inc.
a. Notify the owner that their ECM or TCM was found to have been tuned.
b. Notify the owner that any damage caused by the tuning of the ECM or TCM (including any adverse emissions consequences) will not be covered by Audi of America, Inc. warranties.
c. Obtain the owner's written consent (see attached Control Module Tuning form) for any requested repair - under warranty or outside warranty - that requires flashing that will automatically overwrite the tuned program.