FW: Ignition switch failure mode

DeWitt Harrison six-rs at comcast.net
Fri Jun 19 20:18:51 PDT 2009

Good point. It may be worth observing residual fuel pressure over time for
excessively rapid leakdown. But still, my hunch is it's an electronic issue
since many fuel pressure items have been checked ok. Have I seen Fuel
Pump Relay mentioned yet? (Harder to explain than Hall sensor, IMO,
for intermittent operation.)

I know: PITA. But that's the beauty of CIS. Plus you get very limited
airflow measurement capacity!

DeWitt Harrison
'88 5000CS (Future DIY EFI candidate)

----- Original Message ----- 
From: LL - NY
To: DeWitt Harrison
Cc: Quattro List
Sent: Friday, June 19, 2009 6:50 PM
Subject: Re: FW: Ignition switch failure mode

Leaking injectors?  Injectors leak down after a longer shut off, no pressure
in the fuel lines or dizzy. Takes a bit of cranking to bring fuel pressure
back up enough for the car to go into proper start mode, except by this time
the Cold Start injector is no longer firing, so it's a hard first start.
BTDT, but I forgot the injector replacement interval.

On Fri, Jun 19, 2009 at 2:40 PM, DeWitt Harrison <six-rs at comcast.net> wrote:

  On Fri, 19 Jun 2009 09:59:02 -0400,
  "Geraint Lloyd" <geraintlloyd_qc at yahoo.ca> wrote:

  > [ ... ]
  > I have an intermittent hard start issue with the 1989 - 200 TQA - MC2
  > I had a similar issue a couple of years ago and replaced many, many,
  > many parts then and the problem went away.
  > [ ... ]
  > Essentially the car is hard to start if it has been left for a while,
  > including overnight.
  > It cranks, but either doesn't fire at all or gives an occasional hint of
  > [ ... ]
  > Some background for this time:
  > No codes listed
  > I have been over most of the stuff on SJM's troubleshooting list
  > New over the last 24 months = ecu temp sensor, fuel pump relay, CSV
  > 2nd knock sensor, ISV, fuel filter, check valve, throttle pos switch,
  > dizzy cap, rotor arm,  HT leads, lambda probe. Reset mixture with my
  > CO2 meter,

  The Hall sensor in the distributor can give these symptoms but will throw
  a code. In the MC1 ECU, this code is lost if you turn off the ignition
  retrieveing it. Might be worth a second check next time you get a

  DeWitt Harrison
  '88 5000CS

  quattro mailing list

More information about the quattro mailing list