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

[dwb]

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.

 

[dwb]

I'm interested to see if that had any effect on head pressure now that things have quieted down.

I've been wondering about this too. I'll have to hook up my oil pressure gauge again and compare.

 

[danl]

It does look better, doesn't it? It feels like a different car, much more responsive. @danl I'll give your suggestion a try next chance I get. Thanks!

It looks much better and I know the feeling even if it was 20 years ago when I did the exact same thing. You still have work to do, but you’ve done the hardest part. I ‘think’ your timing will need work next. Apologizes if this has already been asked, but make sure your car profile is accurate, because the next steps will likely draw on that. Engine stuff like compression, cams, turbo, injectors, fuel used, spark plug type, etc.

 

[danl]

That's awesome, seems like noisy HLAs or some were bleeding off too much oil pressure. I'm interested to see if that had any effect on head pressure now that things have quieted down.

It won’t because the hla’s are post regulator and puke all their oil onto the cam lobes no matter if they are filled or not.

 

[dwb]

It looks much better and I know the feeling even if it was 20 years ago when I did the exact same thing. You still have work to do, but you’ve done the hardest part. I ‘think’ your timing will need work next. Apologizes if this has already been asked, but make sure your car profile is accurate, because the next steps will likely draw on that. Engine stuff like compression, cams, turbo, injectors, fuel used, spark plug type, etc.

Profile should be pretty accurate, but I'll go back and review it. Thanks for the reminder. It's essentially a stock 1g setup with 2g pistons (so higher compression). I've been waiting to do much else until I could figure this PK issue out. I have a new Walbro 255 and some new 1000cc injectors sitting on my workbench just staring at me.

 

[dwb]

Use the global sliders to remove 5 degrees of timing from 2500-redline. Take another log and post the file. I’d like to see a change before making suggestions.

Here you go. Managed to do this on my way home this afternoon. I can do another tomorrow if you need a cold engine.

 

[danl]

Put @Stapl3 's timing maps back in it from post #68. Post up the results.

https://www.dsmtuners.com/threads/crazy-knock-under-part-throttle-low-load-open-loop.543706/page-3#post-153891881

 

[dwb]

Put @Stapl3 's timing maps back in it from post #68. Post up the results.

https://www.dsmtuners.com/threads/crazy-knock-under-part-throttle-low-load-open-loop.543706/page-3#post-153891881

Attached. Cold engine, same route as yesterday AM.

 

[danl]

Looks good. So before you changed out the HLA's the knock would spike high and slowly decay over time. That is indicative of phantom knock. What you had going on before reducing the timing but with the new HLA's is the knock would increase over time as you had the engine under load. That is indicative of real knock. The reason for the reduced timing is to get rid of the real knock, which it did as shown in the log from this AM. I know it probably feels slow with reduced timing, but right now we are just trying to get the motor to be quiet before adding timing back in.

You have a few instances of what is likely phantom knock in the 0.6 and 0.7 load factor (left column) usually around 2500 RPM. That probably isn't real knock. I am going to add a file (or at least try) that has the timing tables smoothed out a bit. Try copying in the low and high octane tables to see if this helps get rid of the knock (it probably won't, but it is worth trying). I also added some timing around your idle area to provide a stronger idle.

I noticed that you don't start getting boost till after 3000rpm. What you will likely end up doing is increasing the knock threshold to a couple hundred RPM's before boost builds. Perhaps something like 2800 or 3000rpm and maybe 30-50% TPS to get rid of that low load and low RPM knock. I'd just like to investigate smoothing out the timing map a bit first, as this is the preffered route.

Finally, your TPS does not always stay at 100% during a pull. So something is up with that, possibly the floor mat under the carpet? Overall things look much better but I would spend a lot of time tinkering around getting everything calibrated correctly to ensure great drivability. Things to keep in mind are making sure the timing maps have smooth transitions. You shouldn't see more 2-4 degree jumps at low loads and maybe 1-2 degree jumps between cells at higher loads.

Your next step would be to get a wideband in the car as well. That will help you get the ECU well calibrated and ready for whatever modifications you have planned. I hope this all helps you.

 

[dwb]

Max and Min tables loaded. Adjusted knock control up to 3kRPM and 25% throttle. I have a feeling the TPS fluctuation isn't as much a TPS issue as it is my foot . I tried to pen it to the floor today. Although I do need to verify it's calibration.

Wideband is definitely on my wish list. Hoping to install it in the stock location and simulate narrowband. Unless there is a benefit to install it on the downpipe and keep the stock narrowband.

All the help is very much appreciated!!!

 

[jdxnc]

Max and Min tables loaded. Adjusted knock control up to 3kRPM and 25% throttle. I have a feeling the TPS fluctuation isn't as much a TPS issue as it is my foot . I tried to pen it to the floor today. Although I do need to verify it's calibration.

Wideband is definitely on my wish list. Hoping to install it in the stock location and simulate narrowband. Unless there is a benefit to install it on the downpipe and keep the stock narrowband.

All the help is very much appreciated!!!

Keep the stock o2, simulate as a last resort. More data is good data. If the wideband sensor craps out(and they do), the car will run terrible. Always better to keep the stock sensor and use it for peace of mind.

I would get a wideband now, without it you're shooting in the dark. I wouldn't tune a car without one, stockish or not these days.

 

[danl]

Max and Min tables loaded. Adjusted knock control up to 3kRPM and 25% throttle. I have a feeling the TPS fluctuation isn't as much a TPS issue as it is my foot . I tried to pen it to the floor today. Although I do need to verify it's calibration.

Wideband is definitely on my wish list. Hoping to install it in the stock location and simulate narrowband. Unless there is a benefit to install it on the downpipe and keep the stock narrowband.

All the help is very much appreciated!!!

At the start of your log the intake temp is 66 degrees F and by the end after you do a couple pulls it is over 120 degrees F. Your mod profile says your car is mostly stock. If accurate, that means the temp reading is at the stock MAF pre turbo. That means your turbo is ingesting 120 F air and heating it up. At only 10psi boost, that is over 200 degrees F. The stock SMIC can not deal with all that heat. This is why your timing is quite low and it needs to be to keep real knock at bay. If you can, try to shield the MAF from heat. You have a little bit of background knock but it isn't significant and is quite common. Like most 1g's your battery voltage swings a lot, oh well.

Like others have said, time for a wideband. A front mount and intake piping would go a long way to waking the car up. Then you will need more fuel to compliment that and while you are at it E85 is nice, and so it never ends......

 

[dwb]

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 the purpose of this thread, we can mark this resolved with new HYDRAULIC LASH ADJUSTERS (AKA Lifters).

 

[Vegas Smith]

As mentioned, keep the stock o2 because it's a lot tougher than the bosch lsu sensors and it won't leave you stranded if the wideband dies (and it will die). I would not recommend Innovate widebands either. They don't seem to last very long in many people's experiences.

 

[Blinkyblinx9]

Personally I run my wide band in the factory location. I did this after having issues with 2 wideband sensors crapping out in my downpipe. Apparently if you don't mount them at the right angle based on pipe direction in relation to gravity and distance from a bend you could potentially have issues with moisture repeatedly killing sensors. Swapping a dead sensor to factory takes 10 min, an O2 socket, and my laptop to complete. I have since been on the same Bosch LSU (I think its a knockoff) for 2+ years without issues. I'm not advocating that you go this rout just merely providing my experience on the subject.