I could use some help from the more experienced guys in this forum. I've posted in the general tuning section, but didn't get much advice.

I'm seeing between 1 and 3 counts of knock between 2800 and 3000 rpms and really only when cruising on the highway or any constant load situation and generally ony when transitioning between going up a hill and down a hill.

I've logged it several times, and will post the logs up later but I won't be back home until the weekend. It showed that the knock was really only coming in the 60 to 90 load cells. In response to this, I dropped the timing by about 2 degrees in this range and smoothed it out with the surrounding cells so it was all very linear.

After this I thought it was good and wasn't seeing much knock, but after some WOT pulls with no knock, I saw the same thing again while cruising.

Anyone have any suggestions or help? Everything constructive is appreciated.

I've got a IX with full exhaust, ported head, mani, cossie M2 cams, with an ACT 6 puck sprung clutch and lightened flywheel and a few other things.

 

I fought with this same issue for ages. After confirming it was false knock I found out about the knock multiplier tables that were found that helps raise the noise floor for the knock sensor in the low load area. Proud to say I no longer hate my car haha. It's probably from your head porting and cams in combination creating harmonics in that rpm area.

 

Good info, 2 questions...

How do I confirm it's false knock, and what did you change your values in the knock multiplier tables to?

Thanks!

 

Three tables work to adjust how your car reads knock.

Knock Sum Decay Timer (time on how long the knock condition holds in the ECU) Cutting this in half will allow you to more precisely find the exact load and RPM of your knocksum

Knock Load (load the ECU to start calling for a knock condition) Raising the 2500 and 3000 RPM load values by one or two load cell values will usually help the tip in knock condition.

Knock Multiplier ( low, mid, and high) (Adder that the ECU uses to call for a knock at a given load range) Raising the values by a few points helps to eliminate phantom knock found in cammed and hard engine mount cars.

Hope this helps.

Paul

 

Thanks Paul,

I will try this as soon as I get back.

 

im running the evo 7 rom. Im not seeing a table for knock sum delay timer. How do I get it?

 

Post your ROM ID number. We can get with some of the other experts and find the table for you.

 

98640014

JDM evo7

 

If someone have time, please look for Knock sum decay timer on 88840017
Thanks

 

I just noticed you are from Trinidad. I was stationed there once. Maracas beach is a great place.

I wish I could help you find the address in your ROM for the tables. Below is what I have. Maybe you can use it to find the correct address for yours. These are for the 94170015.

Knock Decay Timer

<table name="KnockSum decay timer" category="Knock Control" address="1784" type="1D" scaling="uint16"/>

Knock multipliers

<table name="Knock Multiplier - Low RPM" level="2"/>

<table name="Knock Multiplier - Mid RPM" level="2"/>

<table name="Knock Multiplier - High RPM" level="2"/>


<table name="Knock Multiplier - Low RPM" category="Knock Control" address="177a" type="1D" level="1" scaling="uint16"/>

<table name="Knock Multiplier - Mid RPM" category="Knock Control" address="24aa" type="1D" level="1" scaling="uint16"/>

<table name="Knock Multiplier - High RPM" category="Knock Control" address="21de" type="1D" level="1" scaling="uint16"/>

Knock Load

<table name="Knock Load" category="Knock Control" address="421a" type="2D" level="2" scaling="Load8">
<table name="X" address="635a" type="X Axis" elements="10" scaling="RPM"/>
</table>

 

can anyone verify if this is the same code for Rom ID 88590015? Everything looks great in mine but the Knock Load table looks a little funny to me

 

At what load are you switching from closed to open loop? Is the knock happening around the changeover point? How do your AFRs look right before the knock occurs?

I had a very similar issue to this and solved it by lowering the open loop changeover point so that the car would run richer than stoich earlier. I think my changeover point is around 80 load or so, whereas stock it is much higher.

 

^ What table controls this point? I also have "tip in" knock when cruising, I think this would fix it.

 

Knock Decay Timer for 90550001?

 

Open Loop Load #1 and #2 under Fueling