ping

[Mark Romans]

You need to watch the timing with some type of scan tool.  I would do this
before spending money on anything else.
Mark  By the way, I know why you would twist the wires.  I have just never
heard of a problem with rfi on the knock sensor circuit.  The ecm is set up
to look for specific frequency so I doubt rfi would trigger knock retard.
Mark
-----Original Message-----
From: David Mulvey <kd6bzn at QNET.COM>
To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
Date: Monday, August 23, 1999 11:36 PM
Subject: Re: ping




> It sounds to me like the knock sensor is NOT working and/or egr problem.
The
> best way to check the knock sensor is to take a plunger handle, and drop
it
> with it's own weight only onto the block near the knock sensor.  Watch the
> timing, (Scan tool) and make sure the ecm is pulling some timing out.  I
> have never heard of twisting the wires.  I have ALL the tech bulletins on
> the L98.  I have tuned the knock sensor a bit by using a bit of teflon
tape

The twisting of the wires is just a simple way of keeping some low frequency
RF from resonating on a stran of wire.  As long as the
wire twists the RF has only very small untwisted sections to resonate.

I checked the EGR valve and the EGR solenoid and the voltage to the
solenoid.  All Ok, a good vaccuum to the egr valve caused the
motor to idle down..  I cleaned out the EGR solenoid gave it a test on a 12
volt power supply. So EGR I think it fine.

I do have one old injector on the side of the engine that doesn't have the
O2 sensor. Could be a suspect.  I have 3 old injectors on
the O2 sensor side, and do not get any mixture errors.

I was wondering about the Knock sensor too.  I do get error 43 which I think
is the code showing that the knock count exceeded it's
limits. An audible ping/knock is also heard at this time.  I guess I was
wondering if the knock sensor maybe was only working a little
not detecting the all of the knocks then causing the computer not to adjust
properly then setting off the MAF voltage too high and/or
too low..  Kinda getting complicated at this point.

I still need to check the ground to the MAF sensor.
I still need to give the knock sensor wires a couple of twists.
I want to replace the 4 old injectors I have, (short on funds at the moment)
AutoZone has injectors for $35 each.
Am I buying crap or are these things workable?
AutoZone also has MAF sensors for $139,
$80 core charge. (got one the other day, same 'ping')
practically everything else is new except for the ESC module.
I figured the ESC is probably working since
I do have a car that runs.. Good assumtion?
I need to see if the knock sensor is working using the plunger stick test.
I haven't gotten into changing ECM values yet.  Will not hesitate if nothing
else seems to work.
"PE vs. RPM table"  =- What's 'PE'?

For the Knock sensor test would I notice a timing change using the plunger
handle and a timing light? I got one of those..


end
----
David Mulvey KD6BZN
Lancaster, CA
(661) 723-0352