I was wondering what could be causing this...

Mostly at part throttle but also at WOT a little, datamaster is not showing any knock count but still pulls up to 1 degree of timing. again i could make it do this mostly at part throttle...but also sometimes pulls timing at WOT with no knock count....why???

Also right at 4000rpm i keep gettin knock retard, i tried pulling some timing and it did the same thing...i tried adding some fuel and it was still there....could this be a rattle in the motor such as piston slap or a misadjusted rocker???

 

come on, no one has an idea in over a day???

 

get a resistor and replace your knock sensor, then see if you still get retard.

 

I have seen this numerous times on my 94 as well. I believe that if at some point knock was detected, the PCM switches modes and retards timing on its own in an effort to prevent knock. Older third gen (730) ECM's called this "Low Octane" mode. I'm not totaly sure the 4th gen PCM uses the same logic but from my observations there is a connection. Mine will retard timing for a while even after the knock counts remain stable. After a certain amount of driving time with out knock counts the PCM reverts back to normal knock and the retard goes away. This phenomenon may be related to the burst knock settings as well but I'm certainly not 100% sure how they affect each other. Again, these are just my observations. I've never really figured out exactly how these things are related. Mine only pulls a degree or so so I'm not too concerned with it. My real knock counts were proven to be false knock so I disable all knock retard for bracket racing.

Steve

 

You might want to try a "search".... this exact topic was discussed in a thread at least two pages long in the last month or so. I get numerous copies of data logs from people to review, and it seems completely normal to see incrementing knock counts that do not cause knock retard, and for knock retard to happen when the knock count is not increasing. My thinking is that there is an AC signal coming from the knock sensor that varies in both amplitude and frequency. Not sure what the "count" represents, even. But its conceivable that its counting frequency over a certain magnitude or something, and that there are other criteria beside knock count used to trigger knock retard.

In the other thread, an mechanic/"tech" suggested that the knock module would repsond to knock by invoking a "permanent" or "burned in" response, and that the knock module would need to be changed to eliminate the knock. I had a hard time buying into that, but he was adamant that it came straight from the GM manual, and he had solved knock problems many times by simply putting in a new knock module.

You might want to try the "search"... I think the thread was on "LT1 Engine Tech".

 

Maybe try eliminating burst knock in the programming. Then see if the retard goes away. It worked on mine, as it was doing pretty much the same thing. After descreening the MAF there was a problem with burst knock; setting it to zero fixed the problem.