Poor running when hot RS4 (B7)

[softail]

Had no joy from the dealer re. the erratic tickover (previous thread) and there are no issues with battery connections as suggested. I've also noticed that the engine seems to want to pull when tootling at 30mph or so -as if extra fuel is being pumped in. I'm a techno phobe and I don't really understand re-mapping etc. Could this be an ECU problem, if so, can anybody suggest where I could take the car in the North West (Liverpool/Manchester area), that could help (and not stitch me up). Warrington Audi have run out of ideas. I've even run on 98octane and this seems to be worse! I'll have to live with this if it's the way the RS4 runs but I didn't have the same problems with my S4 (B7) - that ran like a dream.

[tartan_rob]

Can you explain the issue better please?

[RSjd]

When you or somebody you knows have VAG-Com, you can make some logs in 3rd and 4th gear. At the speed and revs you have problems and also full throttle through the rev range. Logs from block 1,31,3 and 1,103,106. Put them here or by PM, than we can explain something.

BR, Jeroen

[softail]

Can you explain the issue better please?

I seem to be having a problem posting a reply(this is my second attempt). Anyway here goes. I drive a lot in heavy rush hour traffic and when I'm moving at just over tickover (1100/1300) in say 2nd gear, when I dip the clutch to slow down, the revs will drop to about 500/600 then increase to 1100/1300, then drop to 600 and then rise to 800 and stay there until the next time I move. It doesn't happen all of the time but generally 8 out of 10. The situation is worse when I have a lot of electrical draw ie lights, seats,air con etc. I would expect the tickover to drop if I were to suddenly switch on lights etc and the tickover may drop momentarily and then rise to normal (800) which this engine does. In addition I've noticed that if I ease off the accelerator at around 2000/2500, the engine feels as though it wants to pull instead of decelerate, as if extra fuel is being pumped in. It is more noticeable in 4th, 5th and 6th gear. I have had two dealer diagnostics on it and they say the readings are ok. The tec from Warrington Audi drove the car with a computer plugged in for a live test but once again the readings were ok. He seemed to think that the injectors may be pumping more fuel if the engine thinks it is going to stall and this is normal. To put my mind at rest, I drove another RS4 today from a dealer, under the pretence that I was looking for one for my son. I drove the car in the same way I normally do, in the same type of traffic and the car did not have the same problem and was a pleasure to use in traffic. I don't know much about ECUs and remapping but I have driven sports cars for 35 years and I know when an engine is running ok and mine isn't. Any help or pointing in the right direction would be greatly appreciated.

[rAudiguy]

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drive a lot in heavy rush hour traffic and when I'm moving at just over tickover (1100/1300) in say 2nd gear, when I dip the clutch to slow down, the revs will drop to about 500/600 then increase to 1100/1300, then drop to 600 and then rise to 800 and stay there until the next time I move.

No mine does that from time to time when i'm in heavy traffic, if i take my foot off the gas with the clutch out in 1st or second, not sure if it's right, but just keep your foot on the throttle and feather it, that does the trick for me. not sure about the feel of extra fuel being pumped in though. good luck

Jim

[softail]

When you or somebody you knows have VAG-Com, you can make some logs in 3rd and 4th gear. At the speed and revs you have problems and also full throttle through the rev range. Logs from block 1,31,3 and 1,103,106. Put them here or by PM, than we can explain something.

BR, Jeroen

Sounds very complicated but it could be the same information that was taken by the dealers tec, when he plugged in his laptop and took the car out for a drive. I'll be going back to discuss the situation next week as the car is driving me nuts and I'll try and get a copy of the readouts. - Thanks

[RSjd]

I don't know much about ECUs and remapping but I have driven sports cars for 35 years and I know when an engine is running ok and mine isn't. Any help or pointing in the right direction would be greatly appreciated.

I know quiet a lot of ECU's and remapping, daily job
That's why i asked about the logs, than i can see what fuel correction is doing and Airflowmeter values and ignition timing etc..
Block 1 must be between -10% and +10%, when it does >10%, you're Airflowmeter could be bad, when it does >-15%, you can have a leak, e.g. the carterbreathsystem(don't know exactly the english word..).
And cleaning and recalibrating the trottlebody can help.

[tartan_rob]

My car does that from time to time also.

I would say though that you go back to an Audi dealer and one with an RS4 on the forecourt. if need be they can do a side-by-side comparison.

Failing that, get down to a tuner who knows what they are doing.

Rob

[jackwood]

Softail,
I bought our car from Warrington. Will not be going back there if I can help it. They refusd to admit that the Nav could have an RS4 loo on boot up! Had to print out instructions from this site and take them in!!

On this subject, my car certainly doesn't do this. Never has. It also spends a lot of time in traffic in Manchester/Stockport. If you want a comparison car, feel free to contact me and we could meet at a dealers for them to try.

Failing that there is TDiAvant (is that the right guy) based in Manchester that can probably do the VAG-Com log. He is recommended by the guys on here, right guys?

Good luck, but I don't think that sounds right at all.

[ARSEY4]

Maybe the revs are dropping slightly as the fan clicks in when the tempreature starts to rise. Sat in traffic this will happen a lot. Whether the rev drop is excessive I dont know.

[PetrolDave]

I get a similar effect, but ONLY when I'm a bit slow taking the clutch out and the engine revs have dropped to 600ish while the clutch is still "in" - the revs rise to 1200ish and then drop back to normal tickover at 850ish.

Taking the clutch out while the revs are at or above normal tickover avoids it.

It feels like the tickover control loop in the engine management is too slow - it sees the revs drop so it increases the fuelling to stop them dropping further, but then increases the fuelling so much that the revs go too high and has to decrease the fuelling to get the revs back to normal tickover.

[softail]

Many thanks to all who offered advice, Tartan Rob,RSjd,rAudiguy,jackwood,ARSEY4 and PetrolDave, it is much appreciated. Test drove 2 other RS4s last week from other Dealers and they both worked perfectly (at slow speed in traffic anyway), although I have to say one of them had suspension that sounded like a bag of old spanners. My beloved is booked in to Warrington in two weeks (the earliest they have a courtesy car available!) and I'll be offering them the advice that I've received on the Forum. As soon as it's sorted I'll be fitting the non-resonated, valved Millteck that I've got in the garage. Thanks again to everyone and I'll keep you posted.

[softail]

The problem has now been resolved but as usual it doesn't end there. The poor running was caused by the throttle body and the intake manifold not being reset, when the battery was disconnected for the clutch and flywheel replacement. When the car was in for the investigative work I mentioned to the master tech that the engine had a misfire when it was cold.Good enough he emailed Audi Germany and was surprised when a day later they sent him an ECU software upgrade (numbered 0090). The car was due to be returned to the dealer within 2weeks for new front dampers, which were on back order, so I agreed to test the car in the meantime with the proviso that 0080 could be flashed back if 0090 didn't suit. The first thing I noticed was that the engine would tickover at 1600-1800rpm from cold (this is to warm up the cats etc as quick as possible without pushing neat fuel into the engine). The engine doesn't feel as snappy between 2000-4000 and the kick that you get at 5000rpm has now moved up to 5600rpm. I think the change in the engine's characteristics is too big a price to pay for a short term misfire. The car is now back at the dealer having the new dampers fitted and I've asked for 0080 to be flashed back, the problem is that Audi Germany now won't allow the dealer to do this, so it looks like this will be an update for all cars in the near future. My advice is, don't rush in for this update as in my opinion its a retrograde step. I'm still pushing for 0080 but it doesn't look good

[Andyuk911]

Wow ... ugh

[PatrickRS4]

When they upgraded the ECUs it sounds as though the standard settings were not reapplied first, this then causes the ECUs to relearn your driving characteristics. This has been a previous thread on ECU software updates. Mine was reset prior to the 0090 update an is fine. Get your stealer to reset to the standard settings and the spice will return to the driving experience.

Patrick