Knock sensor woes

[D Kunnath]

	Hey all,

	I've posted in the past to get help on other issues in the past few years, 
and while I stay in the shadows most of the time, the wealth of knowledge 
around here is amazing, so I'll have at it again if you all don't mind.

	I just picked up another Camaro (91 Z28, 5.0TPI A4) out in California, and 
like with any "new" used car, there are always a few bugs.  Right now I 
can't seem to clear a code 43, relating to the Electronic Spark Control 
system in the car.  This particular ECM ('730 / ''727) has the ESC module 
moved into the mem-cal, as far as I can tell from the GM Service Manual, so 
I am assuming that the memcal is good because everything else works fine.

	I disconnected the knock sensor when I had the car jacked up and I 
connected an AC voltmeter to the sensor along with grounding to a known 
good groundpoint.  Running the engine at idle produces no AC signal on the 
voltmeter.  I figure that is normal considering the no-load 
condition.  Revving the engine up (engine IS in closed loop) produces no 
signal either.  Now I'm not sure about this.  Is this a normal 
condition?  I traced the sensor wire back to the ECM and it is fine, and 
not running close to spark plug wires.  The engine runs very smoothly both 
under idle and under load.

	The only other thing I can think of is that the car has been in California 
its entire "life", and it does have California emissions.  It has now been 
transplanted to Michigan.  Could there be a certain something with 
that?  I've been running 89 octane gas from Amoco, which has always been 
fairly good in my other TPI cars.

	Any ideas, inputs, points of stupidity that I may have missed?  I wish I 
had a scantool to peek inside the brains, but I know that all of us who 
don't wish for the same.  Whatever you guys can throw at me, I'm all ears...

	Thanks,

	DK

	91 Z28 Convertible, 5.0 TPI A4 2.77
	86 IROC, 5.7L TPI, T56 6-speed, 3.73

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