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ECMlink RESOLVED - Crazy knock under part throttle/low load/open loop

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dwb

Proven Member
813
561
Sep 9, 2021
Broomfield, Colorado
I've attached a data log of my commute to work this morning.

I've been experiencing lots of knock under low load, part throttle, ~2k-3k RPM, and usually open loop. In this log, knock continues into closed loop for a bit. I have to release throttle and roll back into it for knock to stop, and even then it doesn't always stop. This same behavior happens every time the engine is cold, up until either closed loop or full operating temp. Once at full operating temp I primarily see knock under higher load/RPM/throttle as expected which you can see later in the attached log.

Stock fuel system, 91 octane. Stock MAF. Mostly stock car except ECMLink and MBC. Running stock 2g timing maps on a fresh 6bolt with 2g pistons. No other changes to ECMLink from a stock 1g config. No boost leaks, no exhaust leaks. Lifters do not tick (3g revision). I do notice some extra engine vibrations around 3k RPM, which I speculate might be a very slightly bent CAM or sprocket (these CAMs came from a 1g that was rolled over/landed on top of the hood and broke one sprocket). I'll be swapping CAMs and sprockets in the upcoming week(s) to verify this speculation.

I'd appreciate it if someone could take a look at the attached log and let me know if there is something amiss that can be adjusted. I'm an ECMLink noob so please forgive me. Hopefully I've captured the pertinent fields and values.
 

Attachments

  • log.2023.05.17-01.elg
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Solution
Oh yes, the mod-wish-list goes on and on. I'll take intake temps into consideration. Definitely a wideband. It is currently stock with the exception of the mod list in my profile - not much.

I'm just super stoked with how the new HLAs have improved the overall feel, not just throttle response (which is waaay better btw), but it's less 'buzzy' too. I would have replaced them long ago if I had known!

No more crazy knock! You guys ROCK! @danl @We're on Boost @Stapl3 and a few others too, I very much appreciate your time, effort, and patience. I've learned a lot in the process. You guys have given me some good pointers to continue playing with on my own (or a new thread). What a great community to be a part of!

For...
It’s almost certainly false knock. Pull your plugs and you will know for sure. You can have ecmlink ignore the knock sensor under certain parameters if you so choose.
That's what I'm thinking, but being a tuning noob I wasn't sure, so thanks for some clarification. This is why I want to swap CAMs to make sure those aren't the culprit. If not I'll look at tuning it out.

Another thing I've been wondering, since I am running 2g timing maps, do I also need to update the OpenLoopMinOct/OpenLoopMaxOct tables to match 2g? Currently I still have 1g tables in place. Wondering if that might be part of my problem.
 
For the sake of being sure have a thorough once over of your engine. Mine did that for months before my timing belt took a dump. I suspected lifters at first even though I had replaced them. Got really bad about a week ago about 20 min before it shat out on me now I'm sending the head off for 16 new valve guides... I now suspect it was one of the balance shafts but I haven't gotten that far into it yet. Lifters are still pumped up though. Not leaky at all.
 
Curious.. Is your knock sensor in good condition? Replaced it when redoing the engine?
Not when I rebuilt the engine but in late 2019. Less than 10k miles on it. The resin core is still pristine and it's a genuine Mitsubishi part exactly like the original.

For the sake of being sure have a thorough once over of your engine.
I rebuilt the engine last summer. All timing stuff was new OEM. Right around 3k on this engine, runs strong and no weird noises. Only reason I'm noticing this now is because I recently installed ECMLink.
 
I rebuilt the engine last summer. All timing stuff was new OEM. Right around 3k on this engine, runs strong and no weird noises. Only reason I'm noticing this now is because I recently installed ECMLink.
Mine wasn't making any weird noises either. Would usually trigger the check engine light I would say between 2,000 and 3,500 regardless of engine load and stop as soon as I let off the gas. Before it crapped out it began coming on at 1,500 baybe a bit lower. I thought it was sus but it still wasn't behaving oddly besides that. Not down on power, no strange noises besides that sweet sweet stustu swoosh. Timing belt looked fine during my last oil change about a month ago so I doubt it was the belt itself. The tensioner and pullies also looked fine during head removal. Idk man, it never hurts to poke around and try to wiggle stuff though.
 
Mine wasn't making any weird noises either. Would usually trigger the check engine light I would say between 2,000 and 3,500 regardless of engine load and stop as soon as I let off the gas. Before it crapped out it began coming on at 1,500 baybe a bit lower. I thought it was sus but it still wasn't behaving oddly besides that. Not down on power, no strange noises besides that sweet sweet stustu swoosh. Timing belt looked fine during my last oil change about a month ago so I doubt it was the belt itself. The tensioner and pullies also looked fine during head removal. Idk man, it never hurts to poke around and try to wiggle stuff though.
I'll be pulling the timing belt to swap camshafts probably next week so that'll give me a good opportunity to have a look-see. I really don't anticipate finding anything wrong, but you never know.
 
I'll be pulling the timing belt to swap camshafts probably next week so that'll give me a good opportunity to have a look-see. I really don't anticipate finding anything wrong, but you never know.
If one could possibly be bent, make sure you inspect the caps and journals really well.
 
So an anomaly some people refer to as phantom knock is a really iffy subject in these forums. Some people will tell you it's just the sensitivity of our knock sensor and/or how the ECU responds to certain engine noises. Others will tell you that it means that it's hearing something that it shouldn't be and it should not be written off. I personally after what has happened am of the opinion that it MIGHT be something that shouldn't be ignored. There's a lot of speculation in that statement because I don't know if the two events in my case are even related. My personal experience on this subject and with this system in general though years long is limited to just this one car.
 
Start a log on your car (dont start it) and take a wrench and wrap on the block and see if the knock sensor picks up your "phantom" knock on the log.
Most sensor settings are above a certain rpm so you may "have" to have the car running and above the sensors rpm setting (or lower the settings to 0 rpm). Its just a test.
 
Start a log on your car (dont start it) and take a wrench and wrap on the block and see if the knock sensor picks up your "phantom" knock on the log.
Most sensor settings are above a certain rpm so you may "have" to have the car running and above the sensors rpm setting (or lower the settings to 0 rpm). Its just a test.
Dude! Does that work? I thought you could only log ignition retard as a result of knock.
 
Like I said, try it. My sensor is set to anyting above 3500 rpm but I believe I can set it to zero. Let me see..........
Here is my knock sensor setting in ECMLink:
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And here I turned it down to ZERO.
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Set yours to ZERO, save to ECU and then try that test. Write down your settings before you change them since this is only a test to see what happens. Put your settings back when the "test" is concluded. I haven't done this myself but will if I need to so I can check the sensitivity of my sensor and see what it takes to register on a log.
Marty
 
It’s almost certainly false knock. Pull your plugs and you will know for sure. You can have ecmlink ignore the knock sensor under certain parameters if you so choose.
Don't tune out your knock sensor and drive hard. I did to "test" my auto car for knock and I melted 2 pistons, since I had set the sensor to above 8000 rpm. I won't ever do that again. It is why that car is not still a stock auto car. :banghead:
 
Alternatively I found a decent write up on a hobble together device that allows you to listen to your knock sensor. If you're familiar with what knock sounds like as opposed to other engine noises then it might be something you could look into for a definitive answer.
 
Don't tune out your knock sensor and drive hard. I did to "test" my auto car for knock and I melted 2 pistons, since I had set the sensor to above 8000 rpm. I won't ever do that again. It is why that car is not still a stock auto car. :banghead:
Did it go lean or what? And yeah 8k rpm’s is not what I was suggesting haha. Maybe like 3600 and below.

OP did you pull your plugs and look LOL?
 
Did it go lean or what? And yeah 8k rpm’s is not what I was suggesting haha. Maybe like 3600 and below.

OP did you pull your plugs and look LOL?
It "knocked".......but I didn't hear it. The motor told me though. 😞
 
Start a log on your car (dont start it) and take a wrench and wrap on the block and see if the knock sensor picks up your "phantom" knock on the log.
Most sensor settings are above a certain rpm so you may "have" to have the car running and above the sensors rpm setting (or lower the settings to 0 rpm). Its just a test.
I hadn't thought about this, but what would it tell me if it did register knock? What would be a baseline as to when it should and shouldn't register?

Don't tune out your knock sensor and drive hard. I did to "test" my auto car for knock and I melted 2 pistons, since I had set the sensor to above 8000 rpm. I won't ever do that again. It is why that car is not still a stock auto car. :banghead:
OMGAbsolutely a fair warning. If I do try to tune it out I'd go with something like your initial settings 3500/35% and work up or down from there. A typical setting according to the help file is 2200/0% (I'm not connected to the ECU right now so I can't check my current settings, but that sounds about right). When I do see what I believe to be phantom knock, it's way before the turbo has spooled.

OP did you pull your plugs and look LOL?
Not yet. What would I be looking for on the plugs?
 
Something is wrong that's for sure. Your RawKock values go up to 43 in several places in the log and then stay there for several seconds. 43 is the max that raw knock can even go up to, so you are maxing it out.
I wish ECMlink would show us actual voltage from the knock sensor. It might help when trying to look at something like this. I have lots of old logs from a different logger that do show voltage as well as knock counts so you can kind of get a feel for the relation between the two things.
Are you sure your knock sensor is for 1g? The 2g sensor for example has a higher output.

As for the extra vibrations you feel around 3,000 rpm, well, that is where I often log a little bit of knock, like 1.4 degrees of retard or so. Little. But even when I had a more stock engine that I fooled around with and got high knock counts at times, I never "felt" it. If you feel it, I think it's something like you are saying about a bent cam or whatever. And maybe your knock sensor, which is kinda like a microphone, is picking that up.
 
My thoughts were:
Light tap....any knock show up?
Medium tap.....any knock show up?
Hard thunk, same amount of knock or more?
It is a crude way of seeing if the sensor is extra sensitive or not. Since it is mounted on the back of the block, by the roll stop, I wonder if it is picking up "noise" from the car somewhere through the mount but not the engine itself. That is the only reason for the "test".
 
I'll be pulling the timing belt to swap camshafts probably next week so that'll give me a good opportunity to have a look-see. I really don't anticipate finding anything wrong, but you never know.
Does this happen in neutral too? If the cause is mechanical from the engine, you would probably see it in neutral, too.
 
My thoughts were:
Light tap....any knock show up?
Medium tap.....any knock show up?
Hard thunk, same amount of knock or more?
It is a crude way of seeing if the sensor is extra sensitive or not. Since it is mounted on the back of the block, by the roll stop, I wonder if it is picking up "noise" from the car somewhere through the mount but not the engine itself. That is the only reason for the "test".
Makes sense. I might try with a few different materials like a screwdriver handle, wood, wrench, then a small hammer. I have healthy OEM roll stops and mounts so I'm inclined to say it's not from the chassis, but not ruling that out as a possibility.

Does this happen in neutral too? If the cause is mechanical from the engine, you would probably see it in neutral, too.
I can't say I've tried, but pretty easy to see what happens.
 
Something is wrong that's for sure. Your RawKock values go up to 43 in several places in the log and then stay there for several seconds. 43 is the max that raw knock can even go up to, so you are maxing it out.
I wish ECMlink would show us actual voltage from the knock sensor. It might help when trying to look at something like this. I have lots of old logs from a different logger that do show voltage as well as knock counts so you can kind of get a feel for the relation between the two things.
Are you sure your knock sensor is for 1g? The 2g sensor for example has a higher output.

As for the extra vibrations you feel around 3,000 rpm, well, that is where I often log a little bit of knock, like 1.4 degrees of retard or so. Little. But even when I had a more stock engine that I fooled around with and got high knock counts at times, I never "felt" it. If you feel it, I think it's something like you are saying about a bent cam or whatever. And maybe your knock sensor, which is kinda like a microphone, is picking that up.
Absolutely *something* is wrong, but the low load/low RPM knock goes away after it's up to temp. I seem to remember the old TMO logger software did log knock count and possibly voltage. Not sure if that program would still work on an ECMLink chip, though. I still have that cable and software however...
Knock sensor is MD141510, which is the 1g PN.
 
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