Part throttle Knock

[i'm boosted]

I have been tuning my car for the past two weeks to take in account the 2G MAS I installed. My low-mid-high fuel trims hover between 98% and 110%. I have my WOT tuned for 1 count of knock every once an a while. Most likely phantom knock since it's not consistent. My issue is with my part throttle. Just taking off from a stop light or turning onto a street, I am getting 39 to 43 counts of knock between 1900 and 2600 RPM. At the same time my timing goes from 38 to 10. My TP is about 26%. The knock occurs at this RPM everytime like clock work. What can I do to get rid of or reduce it.

Thanks

-Brian

 

[Mackzero]

That's funny, mine does the exact same thing....

If you step on the throttle a little harder than it doesn't do it from a start right?? And if you let off when it is doing it, then push the throttle down to like 50% it doesn't do it right??

 

[i'm boosted]

Exactly. Should I be concerned with that high of a knock count at such a low RPM damaging the engine?

 

[1_bar_goes_far]

My laser was doing the same thing but I fixed it. I looked at the knock code of the ecu and found that it is sorry. The way it is, if you get just a quick spike of knock while at anything above like -10in of hg it would take forever for it to go away. I raised the threshold of knock(how much load it takes to care about knock) and I increased how fast it decrements it(thats why knock goes away fast under low load and slow under high load). The result was absolutely no knock anymore(unless you count wot knock that is like 2-3). So if you have an eprom ecu, you can reprogram the code to do away with pk. But befor I found how to do that, I put a lower temp thermostat and it seemed to help a little. Hope that helps.

 

[i'm boosted]

I think I found out the cause of the knock. On my AFC, I have my 1000rpm and 2000rpm points on the the high TH leaner than the low TH. I set the values to match and at the moment no knock. With the 1G MAF, I ran so rich I never had an issue. I just got back from logging during my lunch break. I will keep ya'll posted.

 

[5150DSM]

1G owners with "phantom knock" issues... The first thing you should check is the knock sensor itself. These cars are 10+ years old and the KS is a wear part. Reach down the back side of the intake manifold next to the throttle body with your left hand. At the bottom of the intake manifold there is a bracket, behind the bracket is the knock sensor, just follow the black wire to where it terminates at the intake mani. Feel around on the back of the sensor, if you get brown goo on your fingers, it's time to change the sensor. The part is only $65.00 and it's fairly easy to change; also, starting with a fresh sensor allows more accurate tuning from the beginning and eliminates the KS as a liability.
Aloha

 

[92tsifwd]

I had the exact same problem 1600-2900 rpms at like 26% th (43 counts and 15 deg of timing) I richened it up and it went away but, the colder it is the knock sometimes comes back I think it is cleared up now but, I will see when it gets colder.

 

[94EclipseGST]

I have a post somewhere here where I explain my same problem and what my particular fix was. Basically, I must have had a small boost leak in the PCV. I did Kyle Tarry's PCV modification and my idle improved, and all part-throttle knock disappeared.

I would have knock counts as high as 40 when I wasn't even boosting. It was driving me nuts. I fiddled with every knob on my MAFT trying to get it tuned out. My fuel trims were all over the place, but that problem has cleared up too since I fixed the leak at the PCV.

 

[92tsifwd]

I am still getting the 43 couts of knock at the same 1500-3000 and I have the safc at 50% high and low from 1600 to 3200. How did you find the leak? How do you do a boost leak test? I have a datalog I could email one of you if you want.

 

[yotabeater]

i too am having this same exact problem. i think mine is from valvetrain noise. i think i have a noisy lifter, and whenever it's acting up the knock sensor picks it up. hey 94EclipseGST, what pcv valve trick are you talking about?? i'd like to know, cuz i'm not sure if it is a noisy lifter or a bad pcv valve.

 

[94EclipseGST]

i too am having this same exact problem. i think mine is from valvetrain noise. i think i have a noisy lifter, and whenever it's acting up the knock sensor picks it up. hey 94EclipseGST, what pcv valve trick are you talking about?? i'd like to know, cuz i'm not sure if it is a noisy lifter or a bad pcv valve.

I don't think Kyle will mind, so I'll post his webpage again.

http://home.comcast.net/~tarryo/kyle/

You'll find what you need in the tech article section.

 

[ho bag]

i had stupid crazy part throttle knock and blamed it on phantom knock as well because i couldnt not tune it out


well i was wrong i added a 255lph fuel pump and what do you knwo its gone.

i guess my old pump was getting lazy and there wasnt enuf fuel preasure to spray fuel properly

in 90% of cases of pk ive seen its not pk but another issue.

BTW teflow tape on the knock sensor threads and a little over tq helps as well