weak spark on 10v turbo (FIXED UPDATE)

[Todd Phenneger]

Heya Everyone,
  For those that care.  My 4ktq is running again.  I FINALLY
Stopped raining on a day I had off to work on the car.  So, I
had no spark.  I had swapped coil, wires, rotor, cap, etc.  To
no avail.  ECU appeared to be ok.  So I swapped in known good
Dist.  Then I lost all spark.  So I suspected ECU.  NOpe, before
I dropped $100 on an ECU I wanted to re-do everything.  I
checked and double checked all ground.  Replaced chassis to
engine ground as I had almost .5 voltage drop under cranking
accross it.  With new ground I get only .2V Drop.  Then I
followed Bently Procedure for checking Dist.  Read Below. 
Pasted from another post.
 I just got my car running.  It was a bad distribuotor.  I
swapped in a known good one and it went from INtermittent spark
to no spark.  So when it stopped raining after a month I tested
the Dist using the Bently Test Procedure.  Guess what, I got 4v
all the time.  Even whent he window was over the sender I still
got 4v.  So I checked the connector of the "known good unit" and
a pin had slid out a little bit.  I pushed it back in place till
it seated and now I had a good signal.  
So check spark.
Good Spark.  But no start.  Pull plugs.
Fuel in cyls, Unplug FP relay and crank with no plugs.
Let  car sit to evaporate fuel.
Put in plugs from 20vt motor sitting in Garage.
Crank with no FP realy.  Car fires a little then cranks.
Replace FP relay now that fuel is burned off.
Car roars to life and settles into nice smooth idle.
YAH YAY HA HA HA.   I Did it.

So,  My "KNOWN" good unit aparently broke in transit. :-) Damn,
well it runs now. Time to start driving it again :-)
l8r
  Todd
(It is still For Sale)

--- Ameer Antar <antar at comcast.net> wrote:
> You should not check resistance in any wires that has voltage
> in it, otherwise you can damage the meter. Maybe you meant
> voltage drop instead of spike in resistance. You can check the
> resistance of the ignition coil at various points and try to
> compare to the Bentley specs. Also, I'd try swapping ignition
> coils. Some auto parts places have a tester to measure spark
> voltage at the spark plug wire. Maybe you have leaky
> injectors? You can be sure about that if you pull the
> injectors and jumper the fuel pump relay connection. With the
> airflow meter flap closed, no fuel should come from the
> injectors, and they should begin to squirt (use a glass jar)
> once the flap is raised after that point. Checking the spray
> pattern will obviously be a good idea too, b/c this may affect
> how well the fuel is mixed w/ air which can cause problems.
> good luck.
> 
> -Ameer
> 
> ---Original Message---
> Date: Tue, 2 Dec 2003 19:06:23 -0800 (PST)
> From: Todd Phenneger <tquattroguy at yahoo.com>
> Subject: weak spark on 10v turbo
> To: Quattro List <quattro at audifans.com>, nwquattro
> 	<audi-nw at u.washington.edu>
> Message-ID:
> <20031203030623.7856.qmail at web12822.mail.yahoo.com>
> Content-Type: text/plain; charset=us-ascii
> 
> Heya everyone,
>   I have a problem with the 4ktq "again".  I HATE CIS!  The
> engien is a 5kt engine, all functions are the same as the MC
> Engine even though my KH is a little different.
> Car ran fine when I parked it but had a stumble on throttle
> tip
> in from idle.
>   Go to move the car to the Garage.  NO Start.  Had been
> parked
> 1-2 weeks.  I have spark and Fuel.  Pulling the plugs yield
> fouled plugs and damp piston tops.
>   After much troubleshooting I have narrowed it unoficially to
> a
> WEAK SPARK.  By that I mean the spark seems visibly weak at
> the
> plugs.  Even at night its hard to see the spark.  I have tried
> swapping known good Plug Wires, Cap, Rotor in and the plugs
> are
> brand new.  I do get a significant voltage drop at the gauge
> when cranking and a large spike in resistance across the power
> wire from battery to starter when cranking.  HOwever, hooking
> up
> my Rover via Jumpers to the Power-Dist block in the Engine
> Compartment (Battery is in Trunk) and grounding to block fixed
> this drop and I still have the same issues.  
>   Next logical step to me is to try a Known Good Coil.  Does
> anyone have any other ideas or things to look at.  I can
> occasionaly get the car to sputter a little but it will not
> run.
>  Any help appreciated.
>   Thanks
>     Todd


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