S6 timing

[HMS-S6]

You can't see knock sensors on any "breakout thingy".
Looking at the knock sensor signal does not tell you if the ECU is doing something with it or not. There is a lot more to knock monitoring - that is why the ECU needs the hall sensor for example etc.

Need proper knock retard logging to make any conclusions whether the ECU is pulling timing back or not. And for that you need either some arhaic factory diagnostics tool or custom code in the ECU.

Ah right. To be honest I no longer have any confidence that this car will ever be right.

[prj]

You can't see knock sensors on any "breakout thingy".
Looking at the knock sensor signal does not tell you if the ECU is doing something with it or not. There is a lot more to knock monitoring - that is why the ECU needs the hall sensor for example etc.

Need proper knock retard logging to make any conclusions whether the ECU is pulling timing back or not. And for that you need either some arhaic factory diagnostics tool or custom code in the ECU.

[HMS-S6]

So it is probably knocking and holding back, this is exactly what my old avant did until we put new rings in it.

Yeh, possibly. I'm hoping that the place it's going to will be able to watch the knock sensors on his breakout box thingy.
Still strange how it's ok sometimes but I guess we'll see.
Be a prime excuse for asking JP to rebuild it into a monster!

[newsh]

So it is probably knocking and holding back, this is exactly what my old avant did until we put new rings in it.

[HMS-S6]

It is still going in on the 21st, this was literally just an observation I made today. The one thing 100% consistent is that when the car is left 10-20 minutes it regains ALL its performance for the first couple of pulls.

[newsh]

Then ignore my suggestion (as usual ) and look elsewhere and don't worry about the digital gauge error. Get an analogue boost/vacuum gauge. Check out hunker7's thread for boost gauge options that I posted recently.

Dave it's not my car and I was only scrating my head.. Can you see a scenario where bot ECUs have the same small error? And he's already got an analogue gauge, that's what he's comparing with.

[twoqu]

As the boost measurement signal is an output from the ecu I doubt whether it is having any effect. The fact that both ecu's display the same indicates that whatever calcucates the display is just a bit out.
Whatever this issue is, it is not consistant with a marginal increase in boost pressure.

[UrS4boy]

Both map sensors in both ECUs?

Then ignore my suggestion (as usual ) and look elsewhere and don't worry about the digital gauge error. Get an analogue boost/vacuum gauge. Check out hunker7's thread for boost gauge options that I posted recently.

[newsh]

You might want to replace your MAP sensor, if only to remove it from the equation.
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Both map sensors in both ECUs?

[newsh]

My mechanical gauge also reads between 0.1 and 0.2 Bar lower than the map sensor in the ECU when the engine is running.
I'm not sure the reading on the dash is valid unless the engine is actually running.


I can't remember, have you checked your atmospheric pressure sensor?

Also suggest you cut the end off the vac pipe at the ecu and remake the joint? The hose can go hard so it leaks even when the clamp seems to be tight.

Take the cap off the WG and check the valve pulls up and down freely, no sticktion, make sure the diaphagm is centred. I did this on the coupe the other day and it runs much better.

[UrS4boy]

G71 Manifold Absolute Pressure (MAP) sensor info

The boost readout on the dash is still 0.1 bar above the mechanical gauge most of the time too. When you look at the atmospheric pressure this does not add up to atmospheric plus boost. With just ignition on it reads 1.1. Both ECU are doing this and running is worse when this condition is present.

To me 1 Bar = 14.5 psig. Atmospheric pressure is around 14.7 psig at sea level. As a result, atmospheric pressure, in Bars, absolute = 14.7/14.5 = 1.014 Bar so 1.1 Bar is a bit more than simply rounding up error but only a 8.5% error (max.) (BUT rounding to a 1.1 display reading could be from 1.051 bar actual reading in which case the effective error would be 3.68%). Not sure what the level of precision of the OE Bosch MAP sensors is supposed to be.

You might want to replace your MAP sensor, if only to remove it from the equation.

G71 Manifold Absolute Pressure (MAP) sensor info:

http://forums.quattroworld.com/s4s6/msgs/20417.phtml

[HMS-S6]

The boost readout on the dash is still 0.1 bar above the mechanical gauge most of the time too. When you look at the atmospheric pressure this does not add up to atmospheric plus boost. With just ignition on it reads 1.1. Both ECU are doing this and running is worse when this condition is present.

[HMS-S6]

Sorry. I think my replies are delayed Dmitri.
The problem is still only under full load (2,500-3,800). Since having I nice exhaust made, at this point the exhaust tone sounds horrid, not like a 5cyl. No like a typical misfire sound but almost like an off beat thunder sound then as it passes 4,000 it richens up and sounds lovely.

[prj]

It's showing 99% and am getting correct boost but yes it's as if it's not switching to wot.

There is NO wot switching in this ECU.
The only thing that is used is the absolute throttle position. If it is showing 99 then its WOT, anything over throttle position about 85 is from a mechanical standpoint.

It does not make ANY difference for the ECU though. It does not care where your throttle is apart from boost control for the target pressure, all fueling and timing is done off of the MAF.

[HMS-S6]

It's showing 99% and am getting correct boost but yes it's as if it's not switching to wot.