S6 timing

[HMS-S6]

A small leak on the vac/boost control line to the FPR would cause lean running on boost (or a bad FPR).

Loose knock sensors, they need to be torqued correctly.

Hi, the car is 100% leak free on vac and boost, I spent literally 2 days sorting lots of small niggles.

I also had a fuel pressure gauge on the car some time back trying to find the fault and it was spot on.

[twoqu]

What is the ecu variant? Is it the 551C or 551E?
I would as suggested revert back to the stock ecu to troubleshoot. No point in stressing the car further. If its not right with stock SW its not going to be right with modified SW.
That leaves us with an on the car issue. Either a sensor or perhaps something even mechanical such as damaged crank or cam pulleys.
If you have substitute sensors you can compare the readings in a controlled environment (indoors!) to see if they are plausible, particularly the air temp one.

[HMS-S6]

What is the ecu variant? Is it the 551C or 551E?
I would as suggested revert back to the stock ecu to troubleshoot. No point in stressing the car further. If its not right with stock SW its not going to be right with modified SW.
That leaves us with an on the car issue. Either a sensor or perhaps something even mechanical such as damaged crank or cam pulleys.
If you have substitute sensors you can compare the readings in a controlled environment (indoors!) to see if they are plausible, particularly the air temp one.

The ECU on the car now is the one that was on the car when new. The crank and cam pulleys are bothe brand new and genuine audi. As is every engine sensor unfortunately. This is the reason it's driving me mad, it's into year 10 now trying to solve this, I'd like someone who is able to read data correctly to look at it as so far, the specialists I've took it to can't be bothered.

[newsh]

Sorry, I can't remember, did you clean the female pins in the MAF connector? You need to take the pins out one at a time and run some very fine wet and dry paper through them.

[HMS-S6]

Sorry, I can't remember, did you clean the female pins in the MAF connector? You need to take the pins out one at a time and run some very fine wet and dry paper through them.

How do I pop them out?
It's strange how every now and again it's pulls perfectly!

[newsh]

Have a read, the first few lines sounds similar to your symptoms.

http://www.s2forum.com/forum/showthread.php?t=24544

[newsh]

ABY pin removal, probably the same as URS http://www.s2forum.com/forum/showpos...6&postcount=45

[twoqu]

Not wishing to compound your misery but when we ask a specific question we are looking for a specific answer.
Just because something is new doesen't mean it wasn't damaged when installed especially when we know how fragile the keyways in the pulleys are. Also even if the sensors are new it doesen't mean the ecu is seing them correctly. There could be an issue with the loom for example.
So what is the resistance of the air temp sensor at say 20C?
The only way to get any more data out of the ecu is via PRJ's SW. It might be worth considering purchasing his SW for the S6 which he developed on his own S6, especially if it could include the data logging.
So in essence are we correct in saying this car has an issue every since you have owned it?

[Error404]

Did you post the dyno graph yet Rich, that might help?
From my basic knowledge of these things it didn't seem that far of where it should be

[prj]

Remember, it's the OP thinking it's knocking.
That does not mean it is.
I don't meant to offend, just stating facts.

This is very easy to check - put some race fuel in, if it's the same, it's not knocking.
Or do a 1:5 mix with xylene as a cheap substitute.

I'm actually 99% sure no timing is being pulled, especially on the stock map, as that barely pulls any timing on 95 RON.

Would look at blocked cat, blocked exhaust, flexi that turned itself inside-out and stuff like that too.
Also, if the MAF->turbo hose is not stock, chuck a piece of pipe into it roughly the same diameter as the pipe and see if it's any better.

[twoqu]

You seem to have eliminated the ecu by trying it on another vehicle. So that does leave us with the "It's on the vehicle" hypothesis.
You claim its ok during warm up which presumably includes some enrichment.
Yet it appears its lean when warm.
So its pointing at something fuel related even though I know you have measured the fuel pressure!
I thought if it knocked the ecu chucked fuel in first, then reduced the timing.
Here is something concrete rather than speculation. I have measured 3 air temp sensors at exactly 20C and they all read 485 ohms. The workshop manual quotes a figure between 450-650 ohms at 20C which is hardly precise.

Having read a previous post the knock detection seems to go retard/more fuel/less boost. The fixed signal retard if failure is detected if true is interesting. However you would have thought that the ecu would flag that up with a code.

[HMS-S6]

Not wishing to compound your misery but when we ask a specific question we are looking for a specific answer.
Just because something is new doesen't mean it wasn't damaged when installed especially when we know how fragile the keyways in the pulleys are. Also even if the sensors are new it doesen't mean the ecu is seing them correctly. There could be an issue with the loom for example.
So what is the resistance of the air temp sensor at say 20C?
The only way to get any more data out of the ecu is via PRJ's SW. It might be worth considering purchasing his SW for the S6 which he developed on his own S6, especially if it could include the data logging.
So in essence are we correct in saying this car has an issue every since you have owned it?

Hi, I can't see a pully have been damaged during fitting as sometimes the car pulls perfectly and sometimes it doesn't.

And yes, the fault has always been there since I had the car.

[HMS-S6]

Remember, it's the OP thinking it's knocking.
That does not mean it is.
I don't meant to offend, just stating facts.

This is very easy to check - put some race fuel in, if it's the same, it's not knocking.
Or do a 1:5 mix with xylene as a cheap substitute.

I'm actually 99% sure no timing is being pulled, especially on the stock map, as that barely pulls any timing on 95 RON.

Would look at blocked cat, blocked exhaust, flexi that turned itself inside-out and stuff like that too.
Also, if the MAF->turbo hose is not stock, chuck a piece of pipe into it roughly the same diameter as the pipe and see if it's any better.

Hi Dmitri

No no, I'm just saying that that's how it 'feels'. Holding back in almost 'stages' of varying degrees. The power sometimes returns in the same manner.
The cats have been replaced, removed completely then replaced again, as has the rest of the system. The MAF to Turbo hose too is stock and new OEM.

[HMS-S6]

ABY pin removal, probably the same as URS http://www.s2forum.com/forum/showpos...6&postcount=45

Hi. I'll try that next I think as I have felt similar faults with other cars which have been a MAF issue. If mine is bad, can you buy the connector from Audi to mate into the loom? I know you can with some modern VAG stuff.

[HMS-S6]

It always seems better for the first few gears after the ecu has been swapped over from one to another too.