Narrowing down my start issue (84 4kq) [with suggested procedure]

[Steve Mills]

Your story below is a variant of a true one concerning Charles Steinmetz,
one of the pioneers of alternating current. See the bottom of the link
below.

http://www.wired.com/science/discoveries/news/2009/01/dayintech_0129

On Tue, Aug 17, 2010 at 12:21 PM, Ben Swann <benswann at verizon.net> wrote:

> Cody,
>
> This is probably why they did away with the WUR and went CIS-E. Indeed, the
> WUR is the
> main reason these fuel pressure tests were used.  CIS-e does not use it
> (WUR) and
> basically there is less need to do fuel pressure tests.  BTDT thinking I'd
> trouble shoot
> CIS-e the scame way as CIS, only to find out it became an irrelevant waste
> of time, and
> all the connections were competely different from CIS.
>
> This reminds me of the story about the old man called out of forced
> retirement to fix a
> critical system so folks could have their Electiricity back.  He used to
> work on the
> system that he helped design and implement.    The officials stood around
> watching as he
> climbs down a manhole with a large screwdriver and comes up less than a
> minute later
> after turning a control switch with the screwdriver.  He hands them the
> $500 bill and
> they complain - Why so much? since all he did was to turn a screw to reset
> a breaker.
> He replied, " Yeah, but I know which screw on which control panel and in
> which manhole
> in which street."  "Come to think of it, don't you think I ought to charge
> you more -
> how much is the outage costing you per minute?"
>
> Ben
> -----Original Message-----
> From: John Cody Forbes [mailto:cody at 5000tq.com]
> Sent: Tuesday, August 17, 2010 10:14 AM
> To: audi at humanspeakers.com
> Cc: Ben Swann; quattro at audifans.com; Johnny B
> Subject: Re: Narrowing down my start issue (84 4kq) [with suggested
> procedure]
>
> I have two five gallon buckets filled to the brim with bad warm up regs
> diagnosed with a
> simple fuel pressure test that takes 5 minutes. Changing parts on hunches
> and well meant
> educated guesses may work for those with parts cars or a fleet of similar
> cars, but in
> the professional world my customers don't want to hear "yeah I changed the
> temp sensor,
> see if that works". There is a test procedure for everything that can lead
> to fixing
> problems by only changing the things that are actually broken 90% of the
> time. I
> understand that not everybody has all of the equipment that a shop does,
> but in this
> case a fuel pressure gauge set is very inexpensive (cant they be had at
> Harbor Freight
> for like $40?) and would take a minute or two to install and KNOW what is
> going on with
> the fuel pump, injectors, DPR, and others. CIS is not like a carb or EFI
> system where
> the system pressure is important, but can be 10% off before it's noticeable
> to the
> driver. The system pressure on CIS is not even very important, but the
> control pressure
> that controls the movement of the metering plate is *critical*.
>
> Now with that all said, is it possible this problem is ignition related? OP
> mentioned
> that the PO changed many things in the fuel system and had it looked at
> many times.
> Could it possibly be that he was barking up the wrong tree? IIRC the car in
> question has
> a basic ignition system (vacuum advance distributor, no ECU), right? It's
> sort of
> unlikely, but maybe the advance is sticking all the way retarded for a
> time?
>
> Also, a smoke test would be pretty useful just to be certain of the vacuum
> system. I've
> made a "smoke machine" before out of a quart paint can with the lid
> soldered shut, some
> WD-40 or ATF as smoke fluid, two pipes soldered to the sides to let air in
> and smoke
> out, a propane torch to make the smoke, and an electric tire pump to do the
> air moving.
> Sounds silly, but I discovered and fixed a few small leaks on a car that
> way.
>
> -Cody (mobile)
>
> On Aug 16, 2010, at 2:35 AM, Huw Powell <audi at humanspeakers.com> wrote:
>
> >
> >> Now that you have gotten to the point of things that Cody and Huw,
> >> and others are pointing out, they may want to suggest clever ways to
> >> do these tests.  Although I have done most of these in my ownership
> >> of CIS cars, in most cases I never needed to go to the point of fuel
> >> pressure tests  since I usually got things sorted by then.
> >
> > I have never - NEVER - seen any need for fuel pressure tests.
> >
> > Vacuum leaks and the resulting maladjusted static fuel mixtures,
> > endlessly.  On almost every CIS engine I have encountered.
> >
> > --
> > Huw Powell
>
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