more on 16v knock sensor diagnosis

[treed2@u.washington.edu (T. Reed)]

[snip]
> Plug the connector back into the knock box and turn on the
> ignition.
>
> Connect the back of pin 12 to ground (find pin 12 before
> you plug the connector back into the knock box).  If your
> fuel pump relay turns on the fuel pumps, your knock box is
> shot.

John,

Thanks for the tip on taking apart the connector - I never noticed that it
came apart!

Are you **SURE** it's pin 12? Pin 12 goes from the knock box to the
ignition control module. Looking at the electrical diagram it seems
much more likely that it's pin 10 (the wire that goes from the knock box
connector to the fuel pump relay) that you would want to ground to test
this. On my car, grounding pin 10 ran the fuel pumps.

> I jumpered my fuel pump relay to ground and drove the car
> that way for almost a year (sometimes its hard to find a
> cheap knock box).  It works, but the ignition is retarded
> (as I mentioned in the other thread) and the fuel pumps
> will be on anytime the ignition is on (no automatic
> shutoff after 2-3 seconds).

Today, I did the following
- checked cam to crank timing: dead on
- checked for resistance in ecu grounds: less than 0.3 ohms
- checked voltage at coil 15(+) while cranking: 10.5 to 11.5 volts
- checked coil resistance: secondary within spec, primary is 1.0 ohms
  (spec is 0.6 to 0.8 ohms) - could this be causing such poor power off
  the line? I'm doubtful that it is, but I suppose its possible. Has
  anyone fixed something like this by replacing the coil??
- connected an LED test light to terminal 4 of the knock box and performed
  bentley test. The light came on when I turned the ignition on, went out
  when I started the car, and did not come on when I revved the engine
  above 3000 rpm - which the bentley says indicates that no faults have
  been recorded. So, it would appear to the untrained eye that my knock
  box is 100% functional except for the FPR output. But I have no idea.

I don't have an adjustable timing light to measure the advance at
different speeds. There aren't any other tests listed in the bentley for
the knock sensor system so I don't know how to continue...

Is there some way I can just disable the entire knock sensor system
without having it always retard the timing? Unplugging the knock
sensor didn't seem to change anything, but I can't say for sure.

The sensor is of type II (the kind with the wire coming out of the center
and the resistance spec of infinity) and was torqued to 15 ft-lbs.

The car is pretty much fine above 2k rpm (knock on wood, get it?) but runs
terrible below that.

Thanks everyone!

-Toby