Projekt 8E

I have threads on QW <a href="http://forums.quattroworld.com/a8d3/msgs/7761.phtml">(link to QW thread)</a> as well which I know some members here have seen, but I need to cover all bases to figure this thing out.

First off, here are the codes. Nothing too descriptive here as far as I can tell. 3 of which appear to be old age and the other is obviously related to the problem, but not the answer.

17981 - Left Engine Mount Solenoid Valve (N144)
P1573 - 004 - Open Circuit
17985 - Right Engine Mount Solenoid Valve (N145)
P1577 - 004 - Open Circuit
18284 - Valve for Torque Support Mount
P1876 - 004 - Open Circuit
17737 - Knock-Control: Cylinder 5
P1329 - 001 - Regulation Limit Exceeded - Intermittent
Readiness: 0000 1101

I have replaced plugs and fuel filter recently.

above 3K RPM I get some hesitation, but over 4K my throttle according to logs cuts to 50% and stays that way until I shift it because the car itself stops producing enough power to get through gears above 3rd on it's own.

I have a fuel pump to replace the driver's side in case that is the culprit for secondary fuel source. I am getting poor readings for g/s from the intake, roughly 100 g/s short. But that could be because the car is cutting throttle. I can't tell what it would actually take in at high RPM.

The diaphragms on the front of the engine are functioning properly, but I haven't verified that the connecting arms that control the internal flaps in the intake manifold haven't broken.

When I log block 032, I get these readouts respectively 1 - 4:
0.8% 14.8% 2.6% -0.8%

This tells me that bank one is lean. Again, still, I am unsure if this points me to a sure area to look at.

Here is a recent log. Unfortunately since I had recently cleared codes, block 032 recorded as 0's, but it does show RPM, throttle cutting to 50% as well as intake g/s

<a href="http://www.canyonero.com/files/1362540003.xls">xls logs</a>

Thanks for making it this far. If you have any advice or ideas, throw them my way please.

itsasecret

Year, Make, Model, engine, and transmission information would help.

Projekt 8E

04 A8L 4.2L auto trans. I'm a 99%'er.

mishar

I would start with cylinder 5 injector. If it is clogged that cylinder would run lean and knock. I am not sure but it wouldn't be unreasonable that computer, after retarding firing as much as possible, cuts off throttle in order to save that piston from melt down. I just wonder if it is that smart.

Projekt 8E

FWIW though, the power loss did start prior to getting this code. It first happened a while back. I still drive it, but I ever run it up unless I am logging or diagnosing. It didn't throw that code until recently when I started logging more and more.

The other hesitation I have is starting with injectors, especially without knowing like you said, if the computer is that smart. Tearing apart the motor if it were something simple and externally available would make me a sad panda.

I should note that I also have received p0420 in the past, and it was usually quite consistently there and it was also there prior to this power loss. Currently it isn't showing up.

MP4.2+6.0

Either plug or more likely coil pack?

itsasecret

Check the coil pack part number it should read 07C 905 715A if not it is not the updated version.

MP4.2+6.0

over on QW with the primary thread to date: http://forums.quattroworld.com/a8d3/msgs/7761.phtml

For other posters may help on background stuff as needed--fuel, throttle stuff, MAF, vacuum, secondary air, etc.

Projekt 8E

Good call. I'll actually add that to the OP.

mishar

Which two are you referring to?