Motor bucks slightly (long)

robert weinberg centaurus3200 at yahoo.com
Thu Nov 12 16:11:26 PST 2009


sweet! thanks steve,

i will follow your procedure and report back next week.

see ya,
Robby




________________________________
From: SAJanesick - Bellsouth <sajanesick at bellsouth.net>
To: robert weinberg <centaurus3200 at yahoo.com>; 200q20v at audifans.com
Sent: Thu, November 12, 2009 4:05:59 PM
Subject: Re: Motor bucks slightly (long)

Robby -

Try it both ways.  I usually start with ignition on - motor off, then again with motor running if I want to see what values are being presented in the 000 block.

I believe the idea is if a fault code has been tripped then it should show regardless or whether or not the engine is running.

Further, and according to Father Bentley, it would seem that you are to clear all the codes, then warm the engine through normal driving.  Then in something like 3rd gear you are to accelerate with WOT from about 2,000 RPM to 6,000 RPM (sorry if the numbers are a little off - it's been a long day without lunch and I just downed an IPA).  Anyway after you run the test, the possibility of faults showing will arise.

What I have found is over time (sometimes just a matter of minutes and sometimes a matter of days) faults codes will accumulate.  They may or, more often than not, may not be significant,  However if you run the WOT test and extract a fault code from that, well my money is on the fact that you have an actual fault.  I think the ECU is somewhat prone to throwing faults and is best judged using the WOT test versus what accumulates over time.

Just an opinion.  Anyone else got any other thoughts?  BTW, I'm using the Ross-Tech tool and software in place of the VAG-COM.  Seems pretty good for what it does although it only give a fraction of information on the 200q20v verses what it says about our A6 Quattro.  I believe it can report on most everything including various personality traits (calculated to the ninth digit) when plugged into the A6 if you sort through enough information blocks.

Later...

           - Steve Janesick
              sajanesick at bellsouth.net


----- Original Message ----- From: "robert weinberg" <centaurus3200 at yahoo.com>
To: "Brandon Rogers" <brogers at terrix.com>; "200q20V mailing list" <200q20v at audifans.com>
Sent: Thursday, November 12, 2009 5:50 PM
Subject: Re: Motor bucks slightly (long)


> there's not harm in having the engine running while hooking the ecu up to the a laptop though, right?
> 
> Robby
> 
> 
> 
> 
> ________________________________
> From: Brandon Rogers <brogers at terrix.com>
> To: robert weinberg <centaurus3200 at yahoo.com>; 200q20V mailing list <200q20v at audifans.com>
> Sent: Thu, November 12, 2009 2:55:24 PM
> Subject: RE: Motor bucks slightly (long)
> 
> With ProDiag (Palm based) it does not really matter, as long as ignition is
> on - but if the motor is not running it can trigger insufficient power to
> ECU and RPM sensor codes.  I like to pull codes after the car has been
> driving - that way if you look at measuring blocks the engine is in normal
> mode - not startup enrichment or anything....
> 
> HTH
> 
> Brandon
> 
> 
> 
> -----Original Message-----
> From: 200q20v-bounces at audifans.com [mailto:200q20v-bounces at audifans.com] On
> Behalf Of robert weinberg
> Sent: Thursday, November 12, 2009 2:12 PM
> To: 200q20V mailing list
> Subject: Re: Motor bucks slightly (long)
> 
> 
> i'm gonna have a friend run the codes with his vagcom software. to confirm,
> the engine should be running, correct?
> 
> Robby
> 
> 
> 
> 
> ________________________________
> From: Brett Dikeman <brett.dikeman at gmail.com>
> To: robert weinberg <centaurus3200 at yahoo.com>
> Cc: 200q20V mailing list <200q20v at audifans.com>
> Sent: Thu, November 12, 2009 11:49:20 AM
> Subject: Re: Motor bucks slightly (long)
> 
> On Wed, Nov 11, 2009 at 6:07 PM, robert weinberg <centaurus3200 at yahoo.com>
> wrote:
>> doubt it's the computer. seriously, change all those $18-$35 sensors,
>> one of them is at fault. the ones that are okay are still 18 years old
>> and could crap out at any point. you can change most of them yourself.
>> they are staring right at you when you open the hood.
>> 
>> i've noticed the audi ECU is not real good at throwing codes. maybe it
>> has too much pride? LOL!
> 
> There is no point in changing "all those $18-35 sensors" when the ECU has
> self-diagnostics.  Plug in a VAG-COM-like tool and you can see exactly what
> values the ECU is seeing for most of the sensors.
> 
> Once in a blue moon I had problems with slow starting/rough starts, and once
> in a blue moon I had problems with weird throttle behavior; the symptom I
> found was that engine braking was odd right near the throttle rest; it was
> greater than if I just took my foot off the gas completely, which was very
> odd.  Both were rare, and so I never bothered looking into them.  I seem to
> recall the throttle stuff only happened when it was below freezing (I know
> for sure it happened once when it was -25 degrees F.)
> 
> Brett
> 
> 
> 
> 
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