she starts, she won't run - 1990 200QA (very long)

[David Michael]

Folks, thanks for all your suggestions and offers of help. It turns out that
the story is worse then I thought. When I wrote my original message, I had
not actually picked up the car from the mechanic. I did so over the weekend,
and am appalled at what has happened to it.  So, of the sordid details
(long):



In November, the car was making a screeching noise when starting. I brought
it to the mechanic (someone who I had never used before, but about whom I
had heard good things). He diagnosed the problem as a throwout bearing, and
we decided to replace the clutch and bearing as well.



The mechanic also mentioned that "the car should run better than it does. It
build boost way too slowly". They did not have time to address it, so I
drove the car off, the noise was gone and the clutch effort much reduced.
BUT – the car was hesitating a bit when cold and generally not running at
100%.  As I had some time,  it was warm, and it had not been done in 30k
miles, I replaced the plugs. I also did the wires for good measure. The
plugs were all perfect – slightly ash covered, but otherwise fine.  The next
morning it finally got cold, and I discovered that the car was quite hard to
start.



Thinking that something needed tweaking, I brought the car back to the
mechanic to get the cold start problem fixed and have the slow boost problem
addressed. They worked on the car for two weeks, and found that supposedly
everything was all OK (control pressures, exhaust back pressure, sensor
resistances etc) with the following two exceptions: I remembered that I had
not replaced the air filter in a long while, and the mechanic found that the
duty cycle signal from mac-14 to the mixture freq valve was not going rich.
I fortunately had a 2nd mac-014, and upon installing that, car was
pronounced fixed.



We picked it up. The next day my wife announced that "it smells like burning
brakes, and is really hard to start". I tried to start it on a 20 degree
day, and could not. So I had it towed back.



They spend another 10 hours on the car (mostly their expense), and decided
that it was the metering head. By this time had lost faith and asked them
put it all back together.



I picked that car up over the weekend (after working 5 minutes to get it
started) and  now it won't go more than 40 miles/hr when cold (even under
full boost), it smells badly of something burning (clutch smells), it
smokes, and is leaking both coolant and oil all over my driveway.



So they took what was one of the best (in my opinion) remaining 200 QAs in New
England (everything worked – A/C, windows, event the parking brake) and
turned it into a $50.00 piece of junk. I am now convinced that it is
something simple. The car has gone from rock solid to appalling way to fast
fro it to be something subtle. So I am going to tackle it one way or
another.



Thanks for listening….


Dave
1990 200 QA - 220K, sadly treated
1998 M3/4 98K
02 MCS 35K