S6 timing

[HMS-S6]

All else I can add, it feels fine, light OR full throttle below 3,000 or above 5,000 and still on LIGHT throttle it's still not right between 3,000 and 5,000. It's not just a WOT problem. It's more an RPM related thing?

[UrS4boy]

All else I can add, it feels fine, light OR full throttle below 3,000 or above 5,000 and still on LIGHT throttle it's still not right between 3,000 and 5,000. It's not just a WOT problem. It's more an RPM related thing?

Is there a possibility that this is normal? Have you driven another C4 UrS4/S6 with the same turbo, injectors and software? Maybe your expectations are greater than reality.

Looking at dyno curves for RS2'd AANs, it always seems that there is a blip around 4400 RPM. Not sure why.

[dkw_dude]

Had a read through this thread, did you test with a new MAF or one from a healthy car?

[HMS-S6]

Hi. Yes at one point owned 3 AAN cars all with standard set up and the other two were WAY nicer than mine. Every now and again mine will pull as it should but it's becoming less frequent. Sometimes there is no desernable feeling of the turbo spinning up at all despite having both gauges reading a healthy stock boost!

And yes this is my 3rd MAF. One being new, makes no difference at all to charictoristics.

[HMS-S6]

And if I do put the mapped ECU in (which I don't now days!) it just aggravates the problem even more!

[HMS-S6]

I accidentally popped the MAF plug off today as it was running and it coughed and died. Is that right?

[newsh]

Yes that's normal.

Sorry the MAF pins didn't fix it

[newsh]

I've just read the whole thread again.

This is a long shot, there's a one way valve in the PCV system that might not be working properly.

Item 10 here

[twoqu]

So on the stock ecu it makes the expected amount of boost 1.1-1.2bar between 3-5K and the fueling goes lean?
Have you experienced any electrical gremins such as low voltage?
One connection between boost and fueling would be the boost pressure on the fpr although I rembember you checking it!
If the ecu is ok on another vehicle and most/all the sensors are new and the engine has no mechanical issues that really just leaves either the loom itself or perhaps a fuel volume issue.
If the loom has an internal issue it might explain the transient nature of the fault. Although you would have thought that when a signal was lost, the ecu would flag it up.
As for fuel volume, some pumps particularly those intended for K jet had high pressure/lower volume whilst the Motronic needs (relatively) lower pressure/higher volume. Not sure what pump you have. I think I floated the theory of some restriction in the pipework before.

[Error404]

How did you test the FPR Rich? I would replace that as a matter of course, its £25 ATEOTD and even a small irregularity with it will cause problems.

[twoqu]

This would be a complete fluke but.. How many wires go into the air temp sensor?
If its 2 - ignore me!
If its 3 - You might have the after run pump connector on the air temp sensor!

http://www.s2forum.com/forum/showthread.php?t=58639

[dkw_dude]

One more suggestion, my 3B was sluggish and holding back, the cause at the time was several loose nuts on the exhaust manifold on the studs that's fixed on the engine. Worth a check. Good luck and fingers crossed for getting your car running right!

[HMS-S6]

No, I've not experienced anything funny like that I'm afraid, the only other thing with the car is that it's awful on fuel (hardly ever see 20mph but this may be normal)

Fuel pressure wise I must admit the only way I've checked it is running the car with a Fuel pressure gauge on the screen so I could see it as I drove and at the time the figure was correct. Also the fuel lines, pump and filter are all new (Audi where possible) although I will try changing it anyway as its a drop in the ocean! Although Parkers quoted me £57!!!

Literally JUST got back from driving it home and it's so weird, booted it in 2nd and it was flat as I expected once just over 3000 was reached, changed at 5000 or so and all the torque returned and it pulled as expected, right into 6th!
Next time pulled well in 2nd into 3rd and flat again, lift off for a second WOT and it came back! Bizarre!!!!

[UrS4boy]

This would be a complete fluke but.. How many wires go into the air temp sensor? If its 2 - ignore me! If its 3 - You might have the after run pump connector on the air temp sensor!

Very good Robin. It is definitely easy to swap those four two pin connectors around and get bad results on an AAN. IAT is a brown connector. N80 Evap Canister purge is blue. But the ISV and After-run pump are both black. Here is the post that I wrote about that (with wire colours):

http://forums.quattroworld.com/s4s6/msgs/252056.phtml

[HMS-S6]

Surely if these were the wrong way round the pump would not run (which it does) and vag-com wouldn't show AIT?