knock sensor problem...fixed, and misc

[mjs <info4mjs@snet.net>]

hi,

i had written in to the "lists" regarding several problems i have been 
encountering on my cars.  i just wanted to thank everyone who responded 
(although i tried to respond to each person individually) with advice.

first of all on my 86 5ktq with regard to a lot of play in the brake 
after the got warm;  it was the master cylinder.  since i'm not that hard 
on the car, i managed to find a remanufactured audi part with a lifetime 
warranty for $60.  within an hour, including bleeding, the brakes are 
just fine.

secondly, i had been experiencing the "check engine" light syndrome on my 
1990 cq.  upon reading out the error codes, i found a few faults.  they 
pertained to the 2 knock sensors, timing reference sensor, and the speed 
sensor.  the speedometer was working fine so i ruled that out.  the car 
seemed to have the timing severley retarted when the light came on so i 
could believe that the reference sensor or the knock sensors were shot.  
i managed to check out the knock sensors with an oscilloscope and found 
that one was very intermittent.  

since time was at a premium and it looked like it was a pita job, i 
brought it to the dealer.  the mechanic confirmed it  and also the other 
faults.  after he replaced one knock sensor and reset the computer's 
memory, he ran the diagnostics again and wolla, no problem.

i asked him why i was getting all of the other indications if only one 
sensor was bad...his response was "sometimes that's what happens".

anyway,  i have 2 fine cars running about as good as they can and just 
wanted to share the info with the list subscribers.   i hope someone can 
use the info.

mike stricker
1990 cq (78k miles)
1986 5ktq (90k miles)