Audi 200 voltage

[Mark Rosenkrantz]

Geraint,

I've seen this type of thing often on older VAG products.  It's not that
you're testing wrong, so don't take me the wrong way:

One of the major clues is that even with a flat battery, it starts well with
a jump from an external power source of some kind.

The issue stems from fairly poor quality primary wiring.  It's not uncommon
for moisture to wick between the insulation and wiring itself, causing
corrosion internally.  Add this to marginal sized wiring, and the wiring
will test OK (in terms of resistance), but it's unable to carry the required
current.  Remember, to show 0 ohms on a multimeter, all you need is a single
strand of good wire (basically).
Maybe overkill, but I usually replace the engine and battery grounds with 2
guage or 4 guage.  Same with the alternator to battery and battery to
starter.

Good quality, modern ropelay wiring should solve your starting issue.

There's one other (less likely) possibility... the starting capacity of the
battery is too low.  Testing voltage isn't enough.  I use a Midtronics
tester, but any "battery" type of place should have a Midtronics or
equivalent.  Very quick to verify the ACTUAL CCA of the battery.

Mark Rosenkrantz
Binghamton, NY
On Thu, Jul 30, 2009 at 10:32 AM, Geraint Lloyd <geraintlloyd_qc at yahoo.ca>wrote:

> Guys n Gals,
>
> I’m still having stress with starting the 200 10v TQA.
>
> Having played extensively with the injection system and replaced or
> repaired
> the following items that were either dead or marginal:
> The igloo (from ECS Tuning), sticky carbon canister solenoid, CSV wiring,
> Michelin man hose, fuel filter, slightly lose rocker cover, wastegate hose
> (mind you it was pretty bloody fast before i fixed that), fuel pump check
> valve, cleaned the ISV, injector leak test, ran all fuel pressure tests a
> couple of times, injector cooling fan switch (vapour lock in CPR
> lines!????!), plugs, cleaned cap, tested ballast in rotor, checked codes,
> ran all output tests, vac lines.......
>
> I’m sure that i missed something there though. In fact i haven’t
> pressurised
> the inlet system for a while......
>
> So it runs pretty well now although there may well be some fuel quality
> issues going on. I noticed that the golf (also K-Jet (pure)) is no longer
> firing within the first second of cranking for the first time in years.
>
> I think that i have a combination of problems though. I think that i can
> eliminate the injection as the source of the hard starting and have now
> directed my attention to the electrical and charging system.
> This is because the battery keeps going dead. And when the battery is
> totally toast then the car starts really well on the emergency jumper
> battery, even though there is no way for it to have built up nonexistent
> fuel pressure etc.
>
> I don't appear to have an out of spec drain, but the battery has been
> flattened a couple of times by junior leaving the rear interior lights on
> overnight.
>
> With a freshly charged battery and the AC off, I have 13.6v at the
> alternator post.
> 13.4 at the jump start post
> and 13.3 at the battery.
>
> With the AC on, this drops to 12.6 at the battery and the AC head unit says
> 11.6v, but then it's a GM unit so it's hard to think that the figures that
> it generates are 100% accurate ;).
> So i'm thinking that either the AC or the radiator fan is sucking the life
> out of the battery, making it progressively harder to start. It's been warm
> and humid in Montréal recently and the car spends most of its time in city
> traffic, so low engine speed and the fan running at force 12.
>
> I have 'done' the splice and replaced all of the +ve wires at the front
> with
> some 10AWG and soldered connections although looking at the voltages, i
> think that i need to clean the starter post. The ground strap was cleaned
> yesterday and had a resistance of <0.01ohms, but is pretty blue so i might
> try and find a cheapo one to replace it with just for a laugh.
>
> What voltage or voltage drop should i see with the AC and the cooling fan
> on?
> Do i have a problem, or is it just that the car needs more highway miles
> and
> less city?
>
> Any help would be appreciated!
>
> Geraint
>
>
>
>
>
>
>
>
>
>
>
>
>
> _______________________________________________
> quattro mailing list
> http://www.audifans.com/mailman/listinfo/quattro
> http://www.audifans.com/kb/List_information
>