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Knock detected but not heard

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Old 06 December 2015 | 06:14 PM
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Default Knock detected but not heard

Just checking over the ESL data and i notice its detecting knock, retarding timing, i only have 7 degress of advance and a very low base ignition, i cant hear any det and my knocklink twitches around the area indicated but remains green still

could it be just tranny noise, engine noise its picking up ?

Old 06 December 2015 | 08:03 PM
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Doesn't the total timing include the knock control map?
If you reset the knock map would it not start detecting the knock again so you could hear it and see on your knocklink?
Those areas where the timings being pulled look to be when you would be hitting some nice boost,have you tried enriching slightly in those areas?
Seeing the odd -1 isn't bad but I would have thought -2 plus would be more than engine noise or shift knock ect.
Old 07 December 2015 | 12:14 AM
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Hi bud

Thing is , you can't clear/reset the knock control map unless you reset the ECU , remove battery lead etc , then it has to learn everything all over again , I'm reluctant to do this , I've refreshed the knock map but it doesn't clear the retarding .

I could richer up a half AFR in those areas and test but again , would need to reset ecu to test .

With det cans on I've never heard any det below 5500 .

My base map around that area is about 24 from memory with advance of 4 I think . So nothing major , why it would need yo retard from 28 degrees I don't know


Cheers






Originally Posted by ossett2k2
Doesn't the total timing include the knock control map?
If you reset the knock map would it not start detecting the knock again so you could hear it and see on your knocklink?
Those areas where the timings being pulled look to be when you would be hitting some nice boost,have you tried enriching slightly in those areas?
Seeing the odd -1 isn't bad but I would have thought -2 plus would be more than engine noise or shift knock ect.
Old 07 December 2015 | 11:56 AM
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I know what you're saying about the ecu reset but it doesn't take that long to relearn,it can also be reset using the laptop so no need to pull leads or plug the connectors up.
I had -3.5's in the same area on the knock map,added 1* and richen up a little,reset ecu and now have 0.75 in the same cells.
I know each car is different but I'm at 27* total timing in that area so only 1* more than you,as you will know tho that 1* can make all the difference.
Old 07 December 2015 | 11:56 AM
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You can reset by switching maps with the reset flag on, no need to remove the battery lead.

If you are sure it is a different noise source, turn knock learning off in that area.
Old 07 December 2015 | 12:01 PM
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Originally Posted by Andy Stevens

If you are sure it is a different noise source, turn knock learning off in that area.
I didn't know you could do this.
I really do need to attend the ESL course! Really hope you do more in the future
Old 07 December 2015 | 12:10 PM
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Originally Posted by ossett2k2
I didn't know you could do this.
I really do need to attend the ESL course! Really hope you do more in the future
That's in the manual, p.27
Old 07 December 2015 | 12:14 PM
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Originally Posted by Andy Stevens
That's in the manual, p.27
Nice one,I'm getting some annoying start up knock events which must be from starter or cold slappy forged engine.
I will get reading again.
Old 07 December 2015 | 10:52 PM
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Ok cheers guys, im guessing its best to add a degree of advance rather than a degree of base timing ?

cheers
Old 07 December 2015 | 11:10 PM
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Did u reset ecu what's the boost and afr at when shows correction
Not sure how adding timing would sort it
Old 07 December 2015 | 11:23 PM
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AFR1s are around 12.9 to 11.7 around the cell area, its hard to pinpoint what cell its refering to as it shows 3800 rpm yet i go from 3600 to 4000 rpm in my tables, the knock control map you cant alter the table values like tyou can afr, For example, the throttle load and rpm ones
Old 07 December 2015 | 11:32 PM
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Originally Posted by Andy Stevens
You can reset by switching maps with the reset flag on, no need to remove the battery lead.

If you are sure it is a different noise source, turn knock learning off in that area.

ok cheers, i have that value set to 1, is that correct ?

and by switching maps, do you mean editing my current map with engine running or literally loading a fresh map on ? doesnt this still require the ECU to learn again ?

cheers
Old 07 December 2015 | 11:46 PM
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Switch car of then swap maps then swap back then ecu resets and relearns if both maps same don't need swap back
engine light blinks once or twice to show what map been set to
Old 08 December 2015 | 12:19 AM
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Ah rite, i dont have switchable maps set up, dont you have to press the throttle pedal twice etc or something, i havent bothered with that.

Just as easy reload the same map from laptop for it to relearn, either way, removing battery lead or other ways, car has to relearn, everytime ive done this ive had crap mpg for the 1st tankfull lol


So, if i do make corrections to the existing map and they work, shouldnt the knock map correct itself and remove the retarding corrections its done already ?
Old 08 December 2015 | 12:36 AM
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Originally Posted by Jaysz
Did u reset ecu what's the boost and afr at when shows correction
Not sure how adding timing would sort it
I think by adding he means pulling a degree of timing.

Originally Posted by The Rig
ok cheers, i have that value set to 1, is that correct ?

and by switching maps, do you mean editing my current map with engine running or literally loading a fresh map on ? doesnt this still require the ECU to learn again ?

cheers
Yes input 1 to reset on map switch,as jaysz If you are running a different map then just switch back to the map 1 or 2 which ever you are using(following the instructions in the manual,not just changing maps on the laptop)
This will reset the ecu,knock control,fuel trims,IAM ect.
Old 08 December 2015 | 12:49 AM
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Have you tuned your closed loop? How do your fuel trims look?
The car shouldn't use a great deal more juice when relearning if you have your closed loop afr's as close to perfect as you can.
tuning closed loop I found you can use the fuel trim map and data log afr's And fuel corrections.
Old 08 December 2015 | 12:49 AM
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I cant turn closed fuel loop off, im running a 95 wrx, closed loop on or off is for like 98 models onwards


At the point of knock (in the table) my total timing is around 23 to 24 degress , with the advance being 7 in the cells.

if i reduce the advance cells down to 6 in the affected area thus retarding the timing (the same as what the ecu is currently doing ) this should reduce the knock ? as it seems to be just when my boost is kicking in, so i may have set too much advance i guess ?

cheers

Last edited by The Rig; 08 December 2015 at 12:50 AM.
Old 08 December 2015 | 01:08 AM
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Personally I take out timing from the base map and leave the advance map as it is but then I'm certainly no expert lol
I was getting a fair bit of knock,especially on spool up but pulling a degree plus enriched a little and now no knock and knock control map is pretty much flat.
Old 08 December 2015 | 01:14 AM
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yeah, when i last mapped my car i reduced base timing as i found it worked better.

so, for now, will reduce base map by a degree in a couple of cells and richen up by say half an AFR in the same cell area and report back

cheers
Old 08 December 2015 | 12:04 PM
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Originally Posted by The Rig
yeah, when i last mapped my car i reduced base timing as i found it worked better.

so, for now, will reduce base map by a degree in a couple of cells and richen up by say half an AFR in the same cell area and report back

cheers

this is the route I would take, if it's just on the edge of spool up then it could be just too much timing for the fuel ratio. Try either reducing the base timing or adding a little more fuel and see what that does for it.

Personally I like a flat advance table - makes the base timing more sensible to look at, but if I'm accounting for different fuels then I'll have say base timing plus 4 degress for the crap fuel, switch to decent fuel and then add more timing through the advance table. That way even if you fill up with crap your base table will run nicely just with no advancement - when you add better fuel in the knock advance will bring in the extra power.

Not sure how the IAM stuph works on ESL yet though (need to read a bit more) but this is the strategy I would use on a newage car as you can adjust how quickly it ramps up/down the IAM and total timing.
Old 08 December 2015 | 07:58 PM
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Ok cheers, guys, ive reduced base timing by 1 degree across a couple of cells and increased the AFR by .5 across the same, reset the ecu and will test over the enxt few days.

heres a snipet of my settings so far

bottom 2 boxes are boost target and boost duty



Last edited by The Rig; 08 December 2015 at 08:02 PM.
Old 09 December 2015 | 09:49 AM
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Bit hard to read your advance map without seeing the IAM learning threshold.
Old 09 December 2015 | 10:28 AM
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Or the total ignition map or fuel map as need to know boost at 0,0.5 and 1 bar as some maps seen 1 showed 0.5 bar at 30 load another showed 0.5 bar at 45 load with maff scaling 600 different on similar cars when maffless not sure time spent getting scaling right

Last edited by Jaysz; 09 December 2015 at 11:15 AM.
Old 09 December 2015 | 02:00 PM
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Originally Posted by Jaysz
Or the total ignition map or fuel map as need to know boost at 0,0.5 and 1 bar as some maps seen 1 showed 0.5 bar at 30 load another showed 0.5 bar at 45 load with maff scaling 600 different on similar cars when maffless not sure time spent getting scaling right
You'd need logs in conjunction with the map for that.

I was specifically wondering which parts of the knock control map were active.
Old 09 December 2015 | 05:36 PM
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Originally Posted by Andy Stevens
You'd need logs in conjunction with the map for that.

I was specifically wondering which parts of the knock control map were active.
Ahh i think i get this now,please correct me if i'm wrong.

If i have 6 input into IAM ignition advance threshold and have 5 input into a cell in the ignition advance table then the knock control will not learn in this cell.
Old 11 December 2015 | 07:15 PM
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Originally Posted by Andy Stevens
You'd need logs in conjunction with the map for that.

I was specifically wondering which parts of the knock control map were active.

My IAM learning threshold is 4 and Ossett2k2 Thats right, if your IAM threshold is 6, anything below wont be read or adjusted in the knock control map.

Andy, does the Knock control Map remove any corrections if i amend the MAP to the better on the fly or do i have to reset the ECU for it to learn again for the knock correction to be removed ? for example, my knock control has -2 in it, if my fuel and timing alterations are good, will it remove the -2 to say -1 or 0.75 for an example or will it always be at -2 until a full reset is done ?

Cheers
Old 11 December 2015 | 11:33 PM
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OK, you are au fait with the CLKC then. No need to reset unless you want to start with a clean sheet, the fine control takes longer to learn than the coarse. It is quick to retard but slow to advance as it is designed defensively.

Originally Posted by The Rig
My IAM learning threshold is 4 and Ossett2k2 Thats right, if your IAM threshold is 6, anything below wont be read or adjusted in the knock control map.

Andy, does the Knock control Map remove any corrections if i amend the MAP to the better on the fly or do i have to reset the ECU for it to learn again for the knock correction to be removed ? for example, my knock control has -2 in it, if my fuel and timing alterations are good, will it remove the -2 to say -1 or 0.75 for an example or will it always be at -2 until a full reset is done ?

Cheers
Old 21 December 2015 | 12:06 AM
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Right

so i reduced Base timing a degree in that area at fault, i also richened up AFR`s

No difference, still picks up knock via ESL and adds in -1 in cells 2600 from load points 33 and 40

So i reduce Advanced timing map by 1 degree in those affected areas, so thats now 2 degrees of timing retarded, result, still picks up knock via ESL yet i cant hear any, my LED knocklink does light up the 2 green LED`s so there is some engine/tranny noise of some sort but i cant hear bacon sizzle via det cans

ive now left the 1 degree of retard in the base map, but gone back to 7 degrees across the board in the advance map, but i have put 6 in the affected cells and increased the IAM Ignition Advance from 4 to 6 in the hope it doesnt adjust the cells with 6 in them.

Bit of a cheat tho as it can detect something but i cant hear it, dilema is, do i let the ESL add in the -1 into the cells that it thinks needs them even tho i cant hear it or do i over ride the ESL, Andy Stephens, any advice ?

Cheers
Old 21 December 2015 | 12:28 AM
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Of corse,if you can't hear the knock on the det cans and you're confident there is no knock then switch off the knock control in that area.
Another suggestion is..... And what I'm thinking of doing(due to a forged noisy cold start knock) is moving the knock sensor to a different position


Old 21 December 2015 | 12:33 AM
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Yeah, thing is, i had my IAM ignition advance set to 4 as i have a few places with 5 and 6 in the cells and also and 7, now ive increased the IAM igntion advance to 6 those cells with 5 and 6 in are now ignored as well, not a problem i guess as there hasnt been any correction to those cells before, but i suppose i have the main advance set to 7 in the important areas of the table so those are still protected by the retarding safety monitoring lol


Ive got my Knocklink knock sensor where you are thinking of putting the standard one, its a good spot to have it, maybe i should swap them around hmmmm

cheers bud



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