Audi back from shop - long

[Mohammed Bhatti <Mohammed.Bhatti@wcom.com>]

For any of you not interested on the outcome of the repair to an 88
80q, delete now.

Syptoms:  
1.
Hard start when engine is warm.  Starts ok when cold.
Starts ok after switching off and then switching on within a couple
minutes.  The longer you wait, the harder it is to start i.e.
long crank times and never on the first try.
2.
In stop-n-go traffic, after engine is hot, have experienced what
appears to be missfiring and bucking when in 1st or 2nd gear.
The misfire occurrs at idle and dissappears at about 15-20 mph.
3.
Idle surge or bounce between 750 rpm and 1200 rpm.
4.
Temperature gauge inoperative and temperature warning light flashes
continuously although all coolant levels are ok.

Outcome:
I took the car into an independant shop (10 min walk from
work).  They diagnosed the multi function switch (# 034 919 369C 
$85) was bad.  Also, the computer temp. sensor (# 0 280 130 053
$50) needed replacing.  Fuel pressure check revealed a sticking
check valve (bought one last year $34, in my car - never had time
to replace).  After replacing, fuel pressure ok.

1.
Fairly warm here in No. Va today.  Went to pick up the car.  Started
it, came up after a slight stumble.  Drove about 22 miles, some
on hghwy and some through DC traffic.  Parked car for about an hour.
Engine is now fairly warm since I also ran the AC.  Came back
and tried starting it.  First attempt, got a "kachung" sound from
the starter (usually happens on my car).  Second attempt, came
right up.  Usually, I would have to crank for 5-10 seconds and
about 3-4 times before it would start.  Drove for another 20 miles
on hgwy and thru traffic.  Stopped for five minutes and turned
car off.  Tried to start, got same sound.  Second attempt fired
right away.  I think my hot start problem has gone away although
I need to look at the starter.  Any suggestions on starter noise?

2.
While driving in traffic, tried to replicate the bucking and misfiring
that I have experienced in warm weather and when the engine gets
hot.  Problem did not re-appear.  Need to test more
on this.  Inconclusive on whether the bukcing and misfire has
gone away.

3.
Idle still not totally stable, but a whole lot better than before.
Noted a slight crack in the vacuum hose that goes from the top
of the manifold to the brake booster when I cleaned out my aux.
vac. pump.  Might replace this hose.  Also will check air flow
mass sensor underneath the air intake boot.  When I replaced the
idle switch last year, I had to remove the air intake boot and 
was able to clean and check the plate on the air flow sensor.  
When I put back everything, the idle was steady at 750 rpm for a 
couple days.  Leads me to believe I need to dig in there some more, 
time permitting.  Idles better.

4.
Temp. gauge ok.  No more flashing from temp warning light.  Temp
gauge moves off the cold position.

I'll report back if any of the above symptoms come back or diminish
in nature.  

mkb
88 80q
mohammed.bhatti@wcom.com