[s-cars] Possible MAF Issue

[pkrasusky at ups.com]

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