1982z28with18s

Using my laptop I noticed I had between 8-9 degrees of timing pulled at idle due to knock. Then after using datamaster I realized it had 5 to 9 degrees of timing pulled at wot. I've got the lt4 km and pcmforless tuning. Bryan suggested swapping back in the lt1 km(thinking the lt4 could be bad) so I did and at idle my knock went to zero and sometimes it jumps up to 3-4. At WOT it's anywhere from 0 to 5. Now, I swapped the lt4 back in and it immediately went back to 8-9 at idle and 5-9 at wot. Do you think the lt4 km could be bad, and the lt1 km could just be picking up that much knock? Or is their something else here that I'm just missing?

Thanks
Justin

mike 96 ws6

i saw more retard w/LT4 than LT1 module in some test i've been doing the last few days. but also some runs with much less. after looking at my data, i believe the inconsistant retard is largely affected by even fairly small differences in coolant temp. what is you data showing as far as this?

ibanez6rg

I'd say get a new LT4, the reason poeple go to LT4s are because the LT1 KM's are more sensative. So I'd say that's why the LT1 KM is still picking up a little knock.

mike 96 ws6

look again. that's what this is about. we have both gotten the opposite result.

ibanez6rg

I'm just saying get/borrow another LT4 KM to see if he gets the same results with the new one.

mike 96 ws6

ibanez6rg

zoso1959

You could just have brian have desensitize your lt1 knock
i'm surprize that he wouldn't have done that in his performance tune.
tony

1982z28with18s

Here's what I came up with today. First off I talked to Bryan from pcmforless and he said that knock burst is programmed out. I went up to my buddies shop and used his snap on scanner for some testing.

First we had my lt4 km in, and at idle it showed between 5-9 degees of spark retard. Cruising it was almost always showing several degrees of spark retard. WOT it had 5-9 degrees of spark retard through the entire rpm range. Mostly stayed between 7-9 though.

Next, we put in another lt4 km and had basically the same results as above except we had a few peaks of 10 degrees of spark retard. Also the entire time the "knock on/off", the knock was showing off at wot, and only came on a few times the rest of the time.

Next, the lt1 km, at idle it was showing up to 4 degrees of spark retard, but for the most part it was none. Cruising it had none to 2 degrees of spark retard. At WOT, it had .1 spark retard until I hit 5300 rpms then the "knock on/off" changed to "on" and it pulled 7-9 degrees of timing. We did another run and at 5300 again it showed knock "on" and pulled 7-9 degrees of timing. Below that no timing was pulled though.

Bryan from pcmforless thinks it the knock sensor, but I'm still not sure. I do have the obdI conversion from him. (thus I still have the obdII knock sensor) Any ideas guys?

My95Z

you could take out your LT1 module and wrap it in teflon tape, it is like adding ear muffs to it, essentially what the LT4 would do but cheaper!

1982z28with18s

Didn't you say teh exact same thing in another post.

mike 96 ws6

mine has pretty much leveled out and i'm getting very little retard running 93 octane. have you tried running some high {100's} octane fuel to see if the knock your getting is actual combustion detonation or rather false knock caused by a loose bolt/bracket ect. or possibly picking it up from you dumping the exhaust in front of the rear axle?

My95Z

umm... yeah. what I post in another post has nothng to do what I say here. He might not have read the other post so now would he know? I am here to help people and not just read posts to see if something has been said or not. [edit]

1982z28with18s

I need to run the 100 octane through it. Might end up doing that next week if I get time. BTW, the exhaust doesn't dump anymore, I need to update my sig.


Dude, its my thread. I started it, and if your not going to give helpful information then GET OUT OF MY THREAD. Your post was completly stupid and had no helpful information in it.

Everyone else, thanks for the help. Once I get it figure out I'll make a post of what solved it.

mike 96 ws6

please do. i'll be interested to know your results.