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Discussion Starter · #1 ·
I logged some readings from my car on the way home today, and I hope that they are way out of norm because I am chipped. I saw readings as high as 55g/l mass air in, 82.7% engine load, an ignition angle of 37.5deg and throttle angle of 13.7% (these last two measurements were at a constant cruising speed of 70mph). I also saw that while idling at a stop sign the retard on all cylinders was 4.8cf, but in my driveway it was 1.5cf. I also saw that under acceleration the fuel injectors were open for an extra 10.88 ms. Are these readings "normal" with a GIAC chipped KO3, or do I have something to worry about?
 

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^^Yeah, what Rusty said.

You'll see mass air readings well over 150 g/s at full throttle & 6000+ rpm.

With a working turbo, your engine load will routinely vary from 25% to 175%. 100% is the theoretical maximum for a naturally-aspirated engine, only. The whole point of forced induction is to get the engine load well over 100%.

Ignition retard at idle is dependent on *dozens* of factors -- in other words, don't worry about it.

Injector on time should vary by approx 20ms over the range of RPM and engine load. 10.88ms on time is a reasonable value for moderately accelerating in normal highway driving.

^^^^^^^^^^^^

log data for a "third gear pull" and post it... that will give us some useful information. (Accelerate from 1200 RPM to 6500 RPM at FULL THROTTLE while remaining in third gear the whole time (use tip mode) -- you'll need about 2 miles of straight, flat road to do this safely.)
 

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Discussion Starter · #5 ·
Rusty, I wish it were so. I have practically no boost, and have troubleshot the crap out of it and am running out of ideas. I am now playing with the ideas of a bad wastegate actuator, a bad n75 valve, a clogged cat, or something else that I haven't thought of. I am getting a rotten egg smell, and Green Hornet had a bad cat that was the culprit last spring. I am currently at sea, so I can't log a full power run until Friday. Someone on here said that running rich can cause my cat to fail, and hopefully the full power run log will determine that. I am prepared to buy a new turbo if I can't get this resolved soon.
 

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Tfek70 said:
Rusty, I wish it were so. I have practically no boost, and have troubleshot the crap out of it and am running out of ideas...
Oh, gosh, you really do have something to worry about. Sorry, I thought you were just playing with your VAG-COM.

If you have no boost, I don't think a WOT run will tell us much. What's your engine code? That will tell us what blocks you need to look at.

Do you have a boost gauge? Have you checked vac lines, etc.? Did you already post this problem and I missed it?
 

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Oops -- same here -- I thought you were playing with the vag-com. Okay...

Load of 82.7% implies that the MAF is not sensing much airflow. This could be for one of two reasons:

1) Bad MAF is under-reporting the airflow
2) You aren't moving much air

I'm leaning toward (2), not (1), because you'd surely have a CEL by now if the MAF was that far off

If you have a non-AEB 1.8T, log blocks 115 & 114 for a second-gear pull -- the boost and wastegate duty data may tell us something.

Also, look at block 032 and tell us what you see in fields 1 and 2.

How's the driveability & the gas mileage?

If you have a boost/vac gage, what vacuum are you reading at idle?

Have you looked in your airbox lately? Maybe there's something blocking the airflow.

You may want to jiggle the wastegate actuator rod to see if there is any play in it (only do this w/ a cold engine).
 

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Discussion Starter · #8 ·
Rusty and Pete, thanks for getting back with me so quickly. I will try to answer your questions as well as possible.

1. I have an AUG engine.
2. I do not have a boost gauge.
3. I have replaced all vacuum hoses (the 4 small ones) with silicone, and replaced the "L" hose.
4. I checked and serviced my Forge DV.
5. I have been posting a lot about this and gotten great response from everyone so far. Kudos to CB5. I was asking the wrong questions though. I think I have it narrowed down to either the wastegate actuator, N75 valve malfunction, clogged cat, or blown turbo.
6. I cleaned the MAF and changed my air filter a week ago and that didn't help. I did the VAG log after I cleaned the MAF and changed the air filter hoping my problem would be solved.
7. I don't have a registered version of VAG Com, so I can't look at blocks 32, 114 & 115. I will try to find someone in the area who does and supply some :beer: .
8. Pete, I think you are right on with the "aren't moving much air" theory. I have been smelling rotten eggs occaisonally and think my cat is shot. My guess is that it is because I am probably running rich. I don't know why though or what would cause this other than a boost leak between the MAF and the turbo.
9. My gas mileage has been fairly normal. I was getting 28.2 per tank but it is down to 27.5 this last tank due to aggressive driving trying to find my boost.
10. My PCV system was fairly clogged leading to a leaky valve cover gasket I have since replaced. My puck valve was absolutely full of turds. I cleaned that out and will do the rest of the PCV system when I get back on dry land. My ship is out until Friday.
11. I will wiggle the wastegate actuator rod on Friday.

TIA,

T. J.
 

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You can also unplug the N75 to wastegate line to check if boost returns, be carefull not to pull too much load because of too much boost and a lean condition.

The two electrical connections on the N75 should measure around 25-35 Ohm.
 

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This may be no help at all, but the diesels often suffer MAF failure which leaves the engine feeling like the turbo is not working. If the MAF is the same unit, I would suspect this. The Bosch MAF element itself (removable from the housing) can be replaced for around 50 GBP with a more reliable Pierburg item.

Please bear in mind, I don't know what kind of MAF is used on the 1.8T, so I may be talking out of my a**, but if you can swap one out with a friend's 1.8T (same engine code), it may help with your diagnosis.
 

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I have an AUG engine, as well. My MAF sensor went bad, and the trim pegged in one direction. The replacement rebuilt unit pegged in the opposite direction. The third one finally held trim within about 1/2 percent of nominal.
 
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