Knock Sensor 90 200TQ

[Huppert, Eric]

Looking for some input or thoughts!!

(90 200TQ)

 

Am in the process of finally getting to the "little things" after doing
injectors, exhaust studs, TB/WP, new cap, plug wires, plugs, suspension etc.
etc.  (parts source has gotten a good chunk of cash in the last year!)

 

After installing the check engine bulb in the gauge cluster I ran the ECU
system diagnostics. Came up with a 2142 "blink fault code" which indicates a
bad #1 knock sensor/open or shorted circuit.

 

Symptoms per Scott M's list are timing retarded, high fuel consumption, low
power or not attaining full boost. Car is getting to 1.4 boost, power seems
alright, but fuel is down to 24 MPG. (My last 5000CS got anywhere from 28-30
MPG on the highway). Check engine light illuminates occasionally under light
acceleration at highway speeds.

 

Got a used knock sensor (correct green one!) last night and installed. Ran
the car and came back to find I still had the same code. Ran a continuity
check on both the ground/shield and sensor wire (#15). Have continuity on
both circuits so wiring (either open or shorted) to ECU doesn't seem to be
the issue.   

 

Only check on the knock sensors (per Bentley for my sons 80Q) is to ensure
no continuity between any circuit on the knock sensor. 

 

Any other possibilities or BTDT besides maybe the knock sensor I just
installed is also bad?          

 

Eric