Re: Dead Audi towed by Acura!

[Robert Houk - SMCC Bos Desktop Hardware <rdh@UrQ.East.Sun.COM>]

   Well, the worst has happened. My Coupe quit on the PA turnpike and had to be
   towed home by my father-in-law's Integra. This is too much embarrassment to
   bear. Q-heads, we must diagnose and fix my car so this never happens again!

You know, I used to get a real kick out of jump-starting all my friends'
fancy German cars from my beat up ole Lotus . . . English Electrics! Ha!

     I had a simialr problem with my 83' TQC. It started doing it just while 
   I was trying to start it. Then it progressed to doing it while I was on 
   the go. Just driving along and then.......nothing! Well, I tried 
   everything (just like you did). Relays, wiring, etc........it ended up 
   being a fuse. Imagine if you can, driving down the road with my 5 point 
   harness sinched and then nothing.....quickly loosen the harness, pull the 
   cover off the back of the "cubby hole", reaching up behind the dash, and 
   wiggleing the fuel pump fuse! Not the prettiest sight, let me tell you. 
   To top it all off, when the pump would finally kick in, the fuse would 
   heat up like a mother (Ouch!). 

     To end my ramblings, I would check the fuse and the associated wiring 
   to the fuse. I ended up just putting a relayed switch in, but that may 
   not suit your needs. 

Yeah, this is basically what I've found. There are about 178 different
unreliable contact points in those damn beasts. They all "corrode", and/or
relax/come loose, etc. In particular, Audi is [***IN***]famous for under-
spec'ing it's wiring/connectors/fuse/relays/etc. I too raised a blister
when I touched the rad fan fuse once . . . the UrQs in particular will
literally *MELT* the main fuse panel or the aux/A/C/control relay/fuse
panel. Everything else runs very HOT to the touch. This heat will in
some cases literally melt your connectors, or just oxidize them (and then
melt them, unless they just stop conducting before they melt, but the
end result is largly the same -- no conductance).

Of those 178-odd contact points, about 117 of them will result in a 
dead engine. (OK, I don't know the real numbers, but there's a "zillion"
of 'em). You gotta go through them one by one until you find the offending
one, and fix it. If you're lucky, you can identify the "sub-system" by
the symptoms (rad fan doesn't work -- only 19 contacts to check out).
Unfortunately, "engine doesn't work" means half the wiring harness of
the car. Any sensor failing to read back will shut the engine off (OK,
wrong, *some* sensors like the crank position and speed ones will shut
your engine off; others like block temp/air temp (as applicable, dif-
ferent engines and different ECUs work differently) will merely make
it run like toilet-fodder). Not just the sensors, but the "ground points"
will do the same.

The fuses really suck -- they run so damn hot that they oxidze, which
just makes them run hotter, which makes them oxidize faster, which . . .
I periodically pull and emory/crocus-cloth the ends of the fuses (the
ones that sink a lot of current, like the radiator fan fuse) to get
back to clean metal-to-metal contacts (as opposed to metal-to-oxide-to-
metal). I once measured .25 volts across the fuse . . . Stupid fuse
design -- very small contact points for high current. DAMN STUPID
fuse design. VERY DAMN **********ING STUPID fuse design.

Example: after weeks of getting the car back in shape, including re-
placing many connectors, cleaning and firming (lightly-crimp to restore
tight contact) connectors, etc., the car was finally almost right, but
still had an intermittent "lean out" and/or stumble. Finally, my me-
chanic said "it's an Audi, I *know* it's a ****ing ground problem".
He took a handy proverbial pointy object and skewered a ground-star
(point where bunch of grounds all came together to a ground lug/bolt
by the coil), and the engine stopped dead. Cut off all the old wire
ends, crimped AND SOLDERED on new lugs, cleaned the paint off the
gound stud/panel, put it back together and it has run solidly for 2
years now . . . (Don't forget the massive ground "straps" that ground
the engine to the body/chassis, and the battery too!)

There is no "easy" answer -- there is no one "oh yeah, they all fail
this way" answer. The whole electrical system *SUCKS*. You just gotta
go through the whole thing piece by piece, wire by wire, connector by
connector until you stumble across today's offender. Extremely time-
intensive. 

Such is life in the fast lane . . .

					-RDH