ping

[CSH-HQ]

>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.

It most definitely will, so will worn out brushes in the heater fan motor,
on a 148 they can be real bad about plug wire rfi......
Grump

>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
>
>