S6 timing

[HMS-S6]

I'll check the fuel pressure Monday first as Dmitri suggests And see what it says, God knows there to go then but o think it'll involve giving Dmitri some money when he can fit me in. Haha.

[prj]

He needs to measure fuel pressure while on a WOT run and see what it is doing.
That will tell whether it's a fuel delivery problem or it isn't.

That said, if load is 140 at WOT, that seems low as well.

[newsh]

From page 22, I wonder if the crankshaft pulley is moving?

Only 124 load at 3600 rpm. Should be more like 180. That's why it doesn't run properly.
Need a boost log.

Probably exhaust blocked (flexi inside out), restriction in intake or engine timed wrong.

[HMS-S6]

From page 22, I wonder if the crankshaft pulley is moving?

I must say. I checked the timing again and again THEN for good measure replaced top and bottom pulley with new Audi parts, torqued up correctly then checked again after a run so I'm fairly sure this is not moving.

Since Dmitri's suggestion to that post I've also driven the car with the other exhaust on, no exhaust at all from DP and have completely taken apart and inspected the intake for restrictions right upto the Turbo.

[twoqu]

http://www.s2forum.com/forum/showpost.php?p=828196&postcount=418

This is whats bugging me and the fact that previously going from max vac to boost allowed the car to perform properly. The sudden drop in the afr could be the difference between a seal and a leak.
Do you have a throtle body assembly to swap over? Its not the most difficult task assuming you have a gasket available.
It seems to me you have umetered air even at idle as its higher than it should be if its in the high 800rpm, the 00561 code suggest the ecu has added the max amount of fuel to correct for this yet still cannot get it down to lambda 1.
Despite claiming that he has told us a million times that the first time I have seen an explanation of load! We know its well below what it should sugesting the engine is not pulling air in through the maf. The ecu is supplying what it thinks is sufficient fuel for the airflow measurement of the maf ergo lean mixture. Although you would have though if the engine was being effectively starved of air (as the load reading indicates) it would be strangled somewhat.
So that leaves us with anything post maf that can allow air in but somehow under boost not let it out! That is the perplexing part.
Once you have tested the fuel pressure, it still does leave the injectors to be verified.

[twoqu]

Another member has solved a mid range hiccup with a new dump valve!

[UrS6 - IamS6]

Fresh second hand one, but going to buy a new one in the New Year, so it can be the best that it can be, now I can appreciate first hand the problem / grief caused by my not working correctly bypass valve.

[UrS4boy]

Bypass Valves vs Dump Valves and impacts on Motronic

Another member has solved a mid range hiccup with a new dump valve!

That would be the result of a torn diaphragm in the diverter/bypass valve. Typically a torn BPV diaphragm can be heard as a "honking" noise during shifts.

Bypass valve info: http://forums.quattroworld.com/s4s6/msgs/20994.phtml

[HMS-S6]

I know what you guys are saying. Unmetered air is THE answer but I've looked and looked and replace and pressure tested a dozen times now. Shame it's not more simple to pop a MAF into the boost side to make sure it's meaduring what goes into the manifold but I believe it's WAY more complex than that.

[UrS4boy]

Injector inserts and seals info

I know what you guys are saying. Unmetered air is THE answer but I've looked and looked and replace and pressure tested a dozen times now.

During your pressure testing, did you use a soapy water spray bottle on the injector inserts? They could be cracked and letting air in under vacuum and out (slightly) under boost. Or the O-rings at the intake manifold ends of the injectors could be ripped, etc. and leaking air in/out.

http://forums.quattroworld.com/s4s6/msgs/266127.phtml

[twoqu]

Unfortunately I don't necessarily understand Motronic Speak! But if its just a simple calculation between what the maf is seing and what it should be reading I make it that you are down 20% whichs sounds considerable.

[HMS-S6]

Dave - yes I did. It was one of my small leaks. All 5 inserts and seals were changed.

Robin - yes. You and me both mate!! But yes. I'm fairly sure if the 'load' message was artificially upped itd run perfectly. But that unfortunately isn't a cure :-(

[HMS-S6]

I seem to remember JP experimenting with a MAF on the boost side but I don't think IT worked out well?

[newsh]

Look at it another way, the throttle is fully open but the car is behaving like it's partly closed.
Could the TPS be bad or set up wrong?

[HMS-S6]

Perfect idea mate. Although it's swapped from my good car AND reads fine on vag-com. Fits the bill though :-s