[s-cars] Possible MAF Issue

Mon Dec 29 13:21:00 PST 2008

Hi Bob,

It is a stumble, car never hints at shutting down.  Sometimes I'll be  
cruising along all is smooth, add a little throttle and get the  
stumble a second later no stumble then another second of stumble.   
When the stumble occurs at low/mid throttle, pressing the pedal  
further down has no effect on the engine power kinda like it's hit a  
wall which made me think of limp mode.  No codes other than the 2121  
closed throttle position(F60) code.  Starts with no issues every  
morning, granted my garage benefits from proximity to the oil burner.   
Thanks Bob.

Regards,

Chris
ripit69 at comcast.net

On Dec 29, 2008, at 3:46 PM, Robert Myers <bob at chips-ur-s.com> wrote:

>
> Chris,
>
> This "stutter"?  More description please?  Is it just a bit of a  
> stumble or does the engine quit completely (just like turning off  
> the ignition switch) for a brief interval and then resume running?   
> If it is the latter I had a similar increasingly frequent visitor  
> which would come and go without explanation.  Turned out to be a  
> failing (and finally completely failed) CPS.  No code was ever thrown.
>
> Bob
>
>
>
> At 02:49 PM 12/29/2008, Chris Hawkins wrote:
>> Hey Paul,
>>
>>
>>
>> Much thanks, hope you had a great Christmas with the fam as well.
>>
>>
>>
>> Can't be the POS because I swapped out to the 034 HO Coil Kit which
>> eliminates the Pieces..OS.  I wish I could capture a moment when  
>> idling to
>> have a chance to pull injector plugs, etc. but it never lasts long  
>> enough at
>> idle to do anything.  Every time I've tried the issue disappears as  
>> I'm
>> opening the hood or before I can even get out of the car.  The  
>> issue happens
>> so randomly it's driving me nuts.  Only time I can reliably  
>> recreate the
>> stutter is under some heavy throttle in 3rd to 6th but pulling  
>> injector
>> plugs is out of the question at those speeds ;-).  Longest duration  
>> was
>> about 2 minutes while driving on the Merritt in moderate traffic,  
>> never had
>> the chance to pull over.
>>
>>
>>
>> MAF has been carefully cleaned with CRC MAF cleaner when I took  
>> everything
>> apart for the upgrades.
>>
>>
>>
>> Do you know how limp mode is achieved, ie; what does the ECU do to  
>> reduce
>> power?
>>
>>
>>
>> Thanks again.  We'll definitely catch up for a spin soon.
>>
>>
>>
>> Chris
>>
>>
>>
>>  _____
>>
>> From: pkrasusky at ups.com [mailto:pkrasusky at ups.com]
>> Sent: Monday, December 29, 2008 8:52 AM
>> To: s-car-list at audifans.com; ripit69 at comcast.net
>> Subject: RE: Possible MAF Issue
>>
>>
>>
>>
>>
>> Chris missed:
>>
>>
>>
>> <<<Date: Sun, 28 Dec 2008 15:59:52 -0500
>>
>> From: "Chris Hawkins" <ripit69 at comcast.net>
>>
>> Subject: [s-cars] Possible MAF Issue
>>
>>
>>
>> Happy Holidays to all.  I'm trying to chase down a miss or apparent  
>> limp
>>
>> mode issue with my '95 UrS6.  Issue began about a month before I  
>> installed a
>>
>> bunch of RS2 upgrades.  Before the upgrades the car had stock K24,
>>
>> injectors, MRC 2+ custom(Paul K. tune) & FMIC.
>>
>>
>>
>> I don't have a VAG-COM(yet, ordered one the other day.  Thanks  
>> Santa.) but
>>
>> the only blink code I got was 2121.  The stutter appears randomly,  
>> at idle
>>
>> or any other throttle position to WOT and at any speed.  It  
>> disappears just
>>
>> as randomly.  It generally doesn't last too long, anywhere from  
>> about 2 sec.
>>
>> to a few minutes.  Fuel filter is new, coils are new 034 HO,  
>> injectors are
>>
>> new 034 RS2 reps, fuel pump is original OE to the best of my  
>> knowledge,
>>
>> however I have a 044 HO pump going in soon, software is the 034 RS2  
>> tune.
>>
>>
>>
>> My initial suspicions were coil or fuel pump but the stuttering  
>> reminds me
>>
>> of a MAF issue I had on a normally aspirated '95 90 a few years  
>> ago.  The
>>
>> sensor turned out to be bad, replaced it with a known good one and  
>> the issue
>>
>> went away.  Code 2121 mentions possible throttle CTP or throttle
>>
>> cable/dashpot adjustments but I'm not sure if that would cause the  
>> random
>>
>> power loss I'm experiencing.  I re-checked all of my work and the
>>
>> connections from the upgrades, before I get knee deep in testing  
>> the coils &
>>
>> fuel pump, etc. are there any BTDT with the same symptoms?  I'm  
>> really
>>
>> curious if I'm looking at a MAF issue instead.  Any spare AAN/RS2/ 
>> P968 MAF's
>>
>> laying around just in case?
>>
>>
>>
>> Chris>>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Hey Chris-
>>
>>
>>
>> This onset / offset misfire sounds verrrrrymuch like a POS failure  
>> that
>> cropped up on me in that car yearsss ago.  It would come / go /  
>> come / go
>> until it eventually (within a few daze) it was a full time miss.   
>> Much
>> different sensation / scenario than my coil failure.
>>
>>
>>
>> To repair I utilized the Get Out Of Jail Free POS "spare  
>> channel" (@ Jim P's
>> in Maine whilst on vacay no less, with Batphone into Domo Oregato Mr.
>> Bobatto to handhold me thru heh heh), so sowwy Charlie - you'd have  
>> to get a
>> new POS.  They're OE in there unless you've swapped so 180k or  
>> whatever
>> ain't shabby.
>>
>>
>>
>> You're lucky if you can get it to miss @ idle, simply jump out and  
>> yank
>> injectors until one don't make no difference - voila - isolated  
>> which jug is
>> 'off'.
>>
>>
>> MAF was OE too and I did run a K&N at one point, mebbe it  
>> 'shortened' it's
>> life or maybe it's just on way out due to newfound RS2 and the  
>> mileage.  Try
>> spraying the MAF connection with contact cleaner, can't hurt.
>>
>> FWIW, CPS was new (splice in from the Steve Y. GP) when I did the  
>> tbelt the
>> month prior to your getting it.  Fuel pump was new at some point  
>> tho it
>> could always fail again / early certainly.
>>
>> My bet's on POS tho based on your symptoms and considering their  
>> age, etc.
>>
>>
>>
>> Hope you had a great Christmas with the family, etc.  Back to der  
>> grind
>> today, grrrr.  Beerz soon!  I reeeeally want to check the beast out  
>> with the
>> RS2 gear heh heh...
>>
>>
>>
>> -Paul
>>
>>
>>
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