asc_up: Yea, been following your thread on revtronix's forum too. While yours seems to be a fuel / maf learning issue, mine seems only to be knocking / retardation related. Various fuel trim tables have values and the AFR's are good for idle and WOT (well WOT is the safe mode map so ~10.5 AFR).
I had the Stage 2 v1 chip in this car for 700 miles, but never had a laptop to see how things were in the ECU. All I know, is that all my same hardware / setup / stage 2 v1 chip worked perfectly in the touring waon...
ECU learning issues
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More data logging of things and for once, I finally caught the ECU knock count / retardation tables with data! (ignore the values 200+... wrong conversion factor).
What mechanically would be wrong with my car/engine to cause all that knocking mid-load / mid-rpm range?
What mechanically would be wrong with my car/engine to cause all that knocking mid-load / mid-rpm range?
'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
Gudgeon knock?
The knock detedtion figure is the number of instances of knock right? And the knock retard is the number of degrees the timing is being retarded by, right?
It seems a bit strange it's go knock correction sometimes even when there is nothing showing in the knock detection in similar positions. In the 1800 and 2200 columns there is quite regular retard when there is no knock detection happening.
Were those figures extracted out of some bigger data body perhaps?
Load is calculated with revs and air flow, so the numbers in those columms won't be consecutive logs will they? Which would I suppose explain why there aren't nessecarily detections with corrections!. Ok. I think I have answered my own question...
As you were.
The knock detedtion figure is the number of instances of knock right? And the knock retard is the number of degrees the timing is being retarded by, right?
It seems a bit strange it's go knock correction sometimes even when there is nothing showing in the knock detection in similar positions. In the 1800 and 2200 columns there is quite regular retard when there is no knock detection happening.
Were those figures extracted out of some bigger data body perhaps?
Load is calculated with revs and air flow, so the numbers in those columms won't be consecutive logs will they? Which would I suppose explain why there aren't nessecarily detections with corrections!. Ok. I think I have answered my own question...
As you were.
No heatshields installed anymore, except the ones on the UP, but those don't rattle and are solid.
Yes, the first table is the amount of knock retardation for each cell and the other table is the number of knock counts the ECU has stored.
Bigger data body? No idea. RevScan just recently added these memory tables and hasn't given much information on how it all works in the ECU. I do know that the tables are reset each time the octane factor changes.
Yes, the first table is the amount of knock retardation for each cell and the other table is the number of knock counts the ECU has stored.
Bigger data body? No idea. RevScan just recently added these memory tables and hasn't given much information on how it all works in the ECU. I do know that the tables are reset each time the octane factor changes.
'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
Hmm. Load is calculated as revs/air-flow, or, air-flow/revs... I can't remember which. So those figures in the columns won't be in chronological sequence. For any particular rev there will be a different load depending on how wide the throttle is and since nobody eases the throttle on so precisely they can keep the revs the same as they climb some ideal hill that allows constantly increasing load, those figures are statisticaly arrived at.
I think you need to be very careful analyzing them. Myself, unless I knew how they were gathered, I wouldn't base any diagnosis on them.
I still think the best figures to use to check the operation of the ignition maps is, TPI, MAF, Load, Revs, Knock correction and Ignition timing. I'd also log IPW, O2 and fuel correction(short term) at the same time.
If you know what the timing is running at, and then how much the knock correction is and how much it pulls the timing by, you can ascertain whether the knock correction is operating properly. If you are logging TPI and load(assuming the temperature is right), you can test whether the timing is correct for the conditions. As far as I am aware that's all we need to know and everything we need to know.
I think you need to be very careful analyzing them. Myself, unless I knew how they were gathered, I wouldn't base any diagnosis on them.
I still think the best figures to use to check the operation of the ignition maps is, TPI, MAF, Load, Revs, Knock correction and Ignition timing. I'd also log IPW, O2 and fuel correction(short term) at the same time.
If you know what the timing is running at, and then how much the knock correction is and how much it pulls the timing by, you can ascertain whether the knock correction is operating properly. If you are logging TPI and load(assuming the temperature is right), you can test whether the timing is correct for the conditions. As far as I am aware that's all we need to know and everything we need to know.
I can tell you from my experience with reviewing the knock info from my Link that knock at mid rpm as load continues to increase. This is where the engine's VE is greatest...which should help keep your AFR's in check, but that's what I noticed.
Primarily Cylinder 4 was the one that I got knock on. Cylinder 3 had a small amount at certain times, but cyl 4 was the main culprit.
Primarily Cylinder 4 was the one that I got knock on. Cylinder 3 had a small amount at certain times, but cyl 4 was the main culprit.
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
I think BSOD is trying to ascertain whether knock being detected is causing his timing to be retarded giving him flat spots.
It seems pretty obvious that there is knocking, indeed there would be something wrong if there wasn't any knocking, the thing he needs to discover though is whether it's causing more retard than it should.
To find that out he needs to know what his running timing is, how many degrees of retard the ecu is calculating should be applied and how much the timing is being retarded by in actual fact.
It seems pretty obvious that there is knocking, indeed there would be something wrong if there wasn't any knocking, the thing he needs to discover though is whether it's causing more retard than it should.
To find that out he needs to know what his running timing is, how many degrees of retard the ecu is calculating should be applied and how much the timing is being retarded by in actual fact.
Ok....I understand....I didn't read all of the thread.
Obviously that's a little more difficult to determine. I'd have to go back and read the entire thread to catch up on what's been already covered.
Obviously that's a little more difficult to determine. I'd have to go back and read the entire thread to catch up on what's been already covered.
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
log1call: Logging all of those parameters at once will be very slow. Not enough data granularity to really see how things are changing relative to each other. Logging 5 parameters gets me 2-3 entries a second. Logging 4 parameters gets me 3-4 entries a second.
I'm trying to ascertain why there is knock getting detected in the mid engine load/rpm range. I can do lots of WOT runs with the engine load near 99% or 1.80+ g/rev and not get any knock retardation logged. yet looking at the ECU's memory knock retard table, it's apparent there is quite a bit in the RPM range from 2200 to 3800 from 46% load to 100%.
Once I get the offset clutch reservoir (when ever the subaru dealership can track one down), *hopefully* it'll solve this issue -- thinking the TMIC is knocking against the cut clutch reservoir and causing false knock. Although, I AM back on the stock ECU with the 440cc injectors. Datalogging has revealed that even at stock/wastegate boost of ~8 PSI, the MAF does get maxed out (or within 0.1V of 5V) under certain WOT conditions. Maybe the ECU just isn't richening up things at the critical time / mid RPM range? The LC-1 wideband does show that part throttle acceleration it often drops to the ~10.5 range; WOT runs are 9 AFR.
I'm trying to ascertain why there is knock getting detected in the mid engine load/rpm range. I can do lots of WOT runs with the engine load near 99% or 1.80+ g/rev and not get any knock retardation logged. yet looking at the ECU's memory knock retard table, it's apparent there is quite a bit in the RPM range from 2200 to 3800 from 46% load to 100%.
Once I get the offset clutch reservoir (when ever the subaru dealership can track one down), *hopefully* it'll solve this issue -- thinking the TMIC is knocking against the cut clutch reservoir and causing false knock. Although, I AM back on the stock ECU with the 440cc injectors. Datalogging has revealed that even at stock/wastegate boost of ~8 PSI, the MAF does get maxed out (or within 0.1V of 5V) under certain WOT conditions. Maybe the ECU just isn't richening up things at the critical time / mid RPM range? The LC-1 wideband does show that part throttle acceleration it often drops to the ~10.5 range; WOT runs are 9 AFR.
'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
Well if you are sure it's revs not load that's causing the knock, then you must have a worn motor. If certain revs cause the knock detection, regardless of load, then it will be piston or gudgeon knock causing it presumably. Have you listened for piston slap when cold and gudgeon knock when warm?
So, have you actually seen the timing being retarded a whole lot?
Have you seen knock detection causing retardation, with no decrease of the knock?
If the knock decreases with the retardation of the timing, then it is tune probably that is the problem.
In a standard system there is a limit how far the timing can be retarded by the knock detection, it's about nine or twelve degrees I think... depends on make and model.
Even if there is a mechanical knock causing knock detection to retard your timing it shouldn't retard it so much that the motor looses a lot of power. So you may have some other problem... not timing.
Also, the knock detection is designed to eliminate false signals. Only signals within a certain frequency range should cause retardation, so rattles will not generally cause it.
So, have you actually seen the timing being retarded a whole lot?
Have you seen knock detection causing retardation, with no decrease of the knock?
If the knock decreases with the retardation of the timing, then it is tune probably that is the problem.
In a standard system there is a limit how far the timing can be retarded by the knock detection, it's about nine or twelve degrees I think... depends on make and model.
Even if there is a mechanical knock causing knock detection to retard your timing it shouldn't retard it so much that the motor looses a lot of power. So you may have some other problem... not timing.
Also, the knock detection is designed to eliminate false signals. Only signals within a certain frequency range should cause retardation, so rattles will not generally cause it.
I'm not exactly sure what piston slap sounds like... but if I take a long metal screw driver and place it on top of each injector, some of them are louder than others... sort of a ticking sound. *sometimes* after a really hard run, they're noticeably louder for a bit.log1call wrote: Have you listened for piston slap when cold and gudgeon knock when warm?
No, I haven't taken off the timing belt to look at the timing when it's off... but from that knock retardation table above, it would only occur mid RPM range above 46% load, which clearly can't be done while revving in neutral in the driveway. How would I see it?log1call wrote:So, have you actually seen the timing being retarded a whole lot?
The Knock Count parameter is really hard to monitor, due to the SSI interface being so slow. If I only log knock count and drive around, then I'm able to catch it in action ( ~12 entries/sec logged). Soon as I add another parameter, it becomes more and more rare for knock count to get logged. Same goes with the FA1 binary pinging parameter. Only plenty of occasions, I've logged the Knock Retard (short term) parameter having 1-3 deg logged while driving under some conditions.log1call wrote:Have you seen knock detection causing retardation, with no decrease of the knock?
Looking at the knock table, lots of the cells are at 8 degrees -- possibly the max for 94 turbo legacy? The numbers in the 200's have the wrong conversion factor -- should be (256 - x) / 4 (e.g. 256 - 230/4 = 6.5 degree retard).log1call wrote:In a standard system there is a limit how far the timing can be retarded by the knock detection, it's about nine or twelve degrees I think... depends on make and model.
Oh but it does loose a noticeable amount of power and "get up and go" feel. Conversely, when I force the ECU back to an Octane Factor of 100% and clear out the knock retardation table (yes, RevScan lets you do this now!) the car feels completely different / better.log1call wrote:Even if there is a mechanical knock causing knock detection to retard your timing it shouldn't retard it so much that the motor looses a lot of power.
I'd be curious what others memory maps look like for stock/modified set ups which are working fine.
'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
in the morning ill update you on the maps but i agree. When i set the obtane factor to 100 runs awesome most annoying thing on earth. I think i might just need the headgaskets and valve seals.
1993 Subaru Legacy L AWD Wagon R.I.P
1994 Subaru Legacy SS R.I.P :(
2004 Nissan Titan LE 4X4
2007 Subaru Legacy GT :)
1994 Subaru Legacy SS R.I.P :(
2004 Nissan Titan LE 4X4
2007 Subaru Legacy GT :)
If you just log ignition timing(as it actualy is as you drive), and knock correction(in degrees).... when the knock detection shows up it should only show for a fraction of a second before it starts to retard the ignition and the ignition timing should be retarded by the number of degrees the knock correction said it should be retarded by. The knock correction should move back towards zero as retarding the timing cures the knock.
If the knock correction shows a large number of degrees for long, if the timing doesn't retard, if the knock does not decrease or cease, then there is something wrong with the operation of the ecu or you have a mechanical knock which doesn't respond to ignition timing
Piston slap is nearly always heard when the motor is cold and in the first few seconds after start-up. The pistons heat up very quickly and expand stopping the noise.
Gudgeon rattle is normaly heard when hot and just as the load comes off the motor after a very light rev in neutral. You need to be under the bonnet to hear the noise. Give the throttle a tiny twist, just enough to rev it to about 1200 revs for a second, then let it off again. Just as the revs peak and start to slow again the gudgeons rattle if they are going to.
If the knock correction shows a large number of degrees for long, if the timing doesn't retard, if the knock does not decrease or cease, then there is something wrong with the operation of the ecu or you have a mechanical knock which doesn't respond to ignition timing
Piston slap is nearly always heard when the motor is cold and in the first few seconds after start-up. The pistons heat up very quickly and expand stopping the noise.
Gudgeon rattle is normaly heard when hot and just as the load comes off the motor after a very light rev in neutral. You need to be under the bonnet to hear the noise. Give the throttle a tiny twist, just enough to rev it to about 1200 revs for a second, then let it off again. Just as the revs peak and start to slow again the gudgeons rattle if they are going to.
*sigh* more failure on progress. It's been a good 150+ mi since I changed the octane factor to 100% and its stayed there. was datalogging today and after getting off the higway (octane factor at 100), stopped at a light, then floored it and slipped the clutch a bit around a right hand corner. Octane factor dropped down to 50% right then. There was ZERO knock retard (short term) logged the while time this was happening. Engine load was at 99% though. OT: heh the MAF gets maxed out at 5500 rpm in 2nd gear too.
Maybe something regarding the transmission / drivetrain is causing it all? the other week I verified the pitch mount was nice and tight. Ive done plenty of other 1st gear WOT pulls the past few weeks with no issues regarding the octane factor.
The following day, driving on the highway I watched as the octane factor slowly rose to 69% over the course of the drive. Checked the knock maps after arriving at work. Seems there is a crazy amount of knocking in the low rpm range. Thinking it must be something mechanical with the engine?
Maybe something regarding the transmission / drivetrain is causing it all? the other week I verified the pitch mount was nice and tight. Ive done plenty of other 1st gear WOT pulls the past few weeks with no issues regarding the octane factor.
Code: Select all
Time | Engine Load | MAF Voltage | Knock Retard (Short Term) | Octane Factor
44:59.0 13.7 0.92 0 100
44:59.4 14.1 0.92 0 100
44:59.7 14.5 0.94 0 100
45:00.0 14.8 0.96 0 100
45:00.4 14.8 0.98 0 100
45:00.7 13.7 0.94 0 100
45:01.0 73 2.34 0 100
45:01.4 47.3 3.12 0 100
45:01.7 63.7 3.34 0 100
45:02.0 73.4 3.46 0 100
45:02.3 82.8 3.75 0 100
45:02.7 91.4 4.32 0 50
45:03.0 99.6 4.67 0 50
45:03.3 99.6 4.94 0 50
45:03.6 99.6 3.26 0 50
45:04.1 16.4 2.42 0 50
45:04.4 14.1 2.17 0 50
The following day, driving on the highway I watched as the octane factor slowly rose to 69% over the course of the drive. Checked the knock maps after arriving at work. Seems there is a crazy amount of knocking in the low rpm range. Thinking it must be something mechanical with the engine?
'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
With constantly data logging every day to/from work, I'm slowly starting to see a pattern. Right now the knock retardation table has started to get pretty crazy (once again, numbers above 200+ are the wrong conversion factor):
Yet not very many knock counts:
2009-10-29_logging.xlsx
2009-10-30_logging.xlsx
In both data logs from the past 2 days, there has been none/minimal knock retardation (short term) logged while driving TO work in the afternoon. Interestingly, driving home FROM work around 12am, I've logged knocking in the 2000 RPM range with little engine load both nights! I suppose this somewhat validates the knock memory tables in the ECU. Driving to/from work is all mostly on the highway at 65 mph. I've highlighted the interesting rows in each Excel sheet (knocking = yellow, high engine load = orange). Planning on doing a compression test Sunday.
Thoughts on knocking in the cold morning with little engine load?
Yet not very many knock counts:
2009-10-29_logging.xlsx
2009-10-30_logging.xlsx
In both data logs from the past 2 days, there has been none/minimal knock retardation (short term) logged while driving TO work in the afternoon. Interestingly, driving home FROM work around 12am, I've logged knocking in the 2000 RPM range with little engine load both nights! I suppose this somewhat validates the knock memory tables in the ECU. Driving to/from work is all mostly on the highway at 65 mph. I've highlighted the interesting rows in each Excel sheet (knocking = yellow, high engine load = orange). Planning on doing a compression test Sunday.
Thoughts on knocking in the cold morning with little engine load?
'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
Yet again, Saturday to work, no knock retardation logged. Driving home there was. I'm driving the same stretch of highway both times and same relative speeds. What the heck?
Did the compression test today, although forgot till after I had reassembled everything that I forgot to open the throttle. Maybe thats why my numbers are so low?
Cylinder 1: 120 psi
Cylinder 2: 120 psi
Cylinder 3: 120 psi
Cylinder 4: 115 psi
Did the compression test today, although forgot till after I had reassembled everything that I forgot to open the throttle. Maybe thats why my numbers are so low?
Cylinder 1: 120 psi
Cylinder 2: 120 psi
Cylinder 3: 120 psi
Cylinder 4: 115 psi
'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
I just don't get it.
2 days ago, was getting fed up with the octane factor stuck at 69% so connected the laptop and found that it had reduced itself to 56%. Lovely. Changed the octane factor to 75%, turned the car off for 10 seconds, back on to verify it was still at 75% and the knock retard/count tables were cleared out.
Within the first 10 miles of highway driving, the octane factor raised itself to 100%. I've been data logging the octane factor to/from work and its stayed at 100%; it's been ~60+ mi now too. Knock retardation / count tables are also all clear. I certainly haven't changed anything hardware wise recently, except for doing a compression test. If I was really having engine or mechanical knocking, you'd think it would've shown itself by now, right?
Anyways, todays logging was sort of weird. I caught the octane factor 8x ABOVE 100% (106, 113, 300, 900). There are no gaps in any of the parameters when these odd-balls were logged either (in case you're thinking cable connectivity issues). Is it possible for higher than 100% values from the ECU?
Additionally, the knock retardation (short term) I logged values of: 1, 4, 8, 16, 32 and 64. Vast majority of these are one-offs with no repeats. Majority of them appear around solid data logging with no gaps in the recorded parameters too. Only 2x was a 1 degree knock retard short term logged for several rows after a 90%+ engine load -- these I would deem valid engine correction. What are valid ranges for this parameter?
2 days ago, was getting fed up with the octane factor stuck at 69% so connected the laptop and found that it had reduced itself to 56%. Lovely. Changed the octane factor to 75%, turned the car off for 10 seconds, back on to verify it was still at 75% and the knock retard/count tables were cleared out.
Within the first 10 miles of highway driving, the octane factor raised itself to 100%. I've been data logging the octane factor to/from work and its stayed at 100%; it's been ~60+ mi now too. Knock retardation / count tables are also all clear. I certainly haven't changed anything hardware wise recently, except for doing a compression test. If I was really having engine or mechanical knocking, you'd think it would've shown itself by now, right?
Anyways, todays logging was sort of weird. I caught the octane factor 8x ABOVE 100% (106, 113, 300, 900). There are no gaps in any of the parameters when these odd-balls were logged either (in case you're thinking cable connectivity issues). Is it possible for higher than 100% values from the ECU?
Additionally, the knock retardation (short term) I logged values of: 1, 4, 8, 16, 32 and 64. Vast majority of these are one-offs with no repeats. Majority of them appear around solid data logging with no gaps in the recorded parameters too. Only 2x was a 1 degree knock retard short term logged for several rows after a 90%+ engine load -- these I would deem valid engine correction. What are valid ranges for this parameter?
'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
A theory on the knock: the ECU is supplying the same fuel/load in the morn as the afternoon. Cooler air is denser and would, therefor, require more fuel to achieve the same burn rate. In other words, you might be running just lean enough in the wee hours to get some knock.
Do you have a wideband? If so, can you datalog and reference these knock recordings against O2 readings?
Do you have a wideband? If so, can you datalog and reference these knock recordings against O2 readings?
[quote="RJ93SS"]u fail, epicly[/quote][quote="evolutionmovement"]Don't do drugs, kids, men may not need nipples, but we look a lot funnier without them.[/quote]
WOW!!! this is a great thread... I'm only N/A, but learning what the ECU sees and uses to make it's corrections id nice.
Just on a WAG my wife's '90 N/A 4EAT was stumbling, surging at idle, and stalling. Would run great all day, then stumble (tach drop from 2200 to 600 and recover), or run fine then die at a stop. Swapped the MAF with mine and hers is running great. I bought a junkyard MAF for mine, reset the ECU, and both are GTG...
Just on a WAG my wife's '90 N/A 4EAT was stumbling, surging at idle, and stalling. Would run great all day, then stumble (tach drop from 2200 to 600 and recover), or run fine then die at a stop. Swapped the MAF with mine and hers is running great. I bought a junkyard MAF for mine, reset the ECU, and both are GTG...
'90 Bermuda Blue L Wagon (Wife's),
Auto, AWD, Now with 275K + miles!
2005 Outback, 2.5 AWD (wife's new daily)
Auto, AWD, Now with 275K + miles!
2005 Outback, 2.5 AWD (wife's new daily)
epicfail: Yes, I have a wideband, but RevScan is not able (yet) to datalog it 
. Could use EvoScan, but its conversion parameters aren't the same as revscan so harder to compare data... at least for some of the parameters.
I just got my injectors cleaned, which found out 3 of them where flowing at 420cc instead of the revtronix programmed/expected 440cc. That has now spawned off a new major problem of an injector leak, which I'm still trying to resolve. Anyways, just got an updated stage 2 chip which compensates for my lower injector flow rate, lowers the power enrichment threshold and increases the fuel trim learning to +/ 50%. Once I get the injectors, updated chip, etc all working, then I can continue to tackle this damn knocking/learning issue. *sigh*
tahiti350: Soon as I get things running again, going to data log the Autecs MAF to see if its voltage to airflow has a linear response, or something else up with it. Note: this is the same MAF I used flawlessly on my TW though. My car has never experienced the symptoms you describe though.
. Could use EvoScan, but its conversion parameters aren't the same as revscan so harder to compare data... at least for some of the parameters.I just got my injectors cleaned, which found out 3 of them where flowing at 420cc instead of the revtronix programmed/expected 440cc. That has now spawned off a new major problem of an injector leak, which I'm still trying to resolve. Anyways, just got an updated stage 2 chip which compensates for my lower injector flow rate, lowers the power enrichment threshold and increases the fuel trim learning to +/ 50%. Once I get the injectors, updated chip, etc all working, then I can continue to tackle this damn knocking/learning issue. *sigh*
tahiti350: Soon as I get things running again, going to data log the Autecs MAF to see if its voltage to airflow has a linear response, or something else up with it. Note: this is the same MAF I used flawlessly on my TW though. My car has never experienced the symptoms you describe though.
'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
-
longassname
- First Gear
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- Contact:
Not me. The Revtronix chip re-maps the Autecs MAF for the increased air flow scaling.
Yes, there are others on the forum who use the JECS MAF with the 'ground mod' and stock ECU which is a terrible idea.
Yes, there are others on the forum who use the JECS MAF with the 'ground mod' and stock ECU which is a terrible idea.
'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.
-
longassname
- First Gear
- Posts: 60
- Joined: Mon Nov 30, 2009 5:48 pm
- Location: Miami, FL
- Contact:
I had missread something that made me think you had switched mass air meters without changing chips and that that was normal practice.
Mass air meter voltage response to airflow is far from linear. ECUs use a very detailed table particular to the meter to translate it's voltage into the airflow measurement.
Mass air meter voltage response to airflow is far from linear. ECUs use a very detailed table particular to the meter to translate it's voltage into the airflow measurement.
[url=http://www.ecutune.com/pics/10-08-03-uncropped.jpg]Michael Emery, MBA, MS[/url]
[url=http://www.ecutune.com/pics/svx-drift-r.jpg]94 SVX LSI, Ebony Pearl profile[/url]
[url=http://www.ecutune.com/pics/svx-drift-r.jpg]94 SVX LSI, Ebony Pearl profile[/url]
The sad saga continues...
Since my last set of posts, I have:
* gotten the injectors cleaned and flow tested (434cc)
* received an updated Stage 2 chip (v3) which is programmed for 434cc and a sooner fuel enrichment.
* Re-installed the MBC and lowered boost to ~10 PSI.
* bought/installed another OEM knock sensor
* re-wired the knock sensor using microphone wire from the engine bay to the ECU. Connections are soldered, headshrinked, wrapped in electrical tape and automotive conduit.
I'm convinced now that everything related to the knock sensor circuit is functioning properly.
With data logging (either with Revscan or EvoScan), I can see that knocking is STILL a problem. The frustrating/confusing thing is that it's not constant. Some times, a WOT run will have the 'knock retardation' parameter logging up to 15* BTDC, other times it'll only be in the 1-2* range and some times ZERO retardation is logged. Knock retardation is ONLY logged while on boost, so it's not like I have something randomly banging around in the engine bay.
Mike @ Revtronix says that a few degrees of retardation, I should be actually hearing the engine pinging, yet I never do ever (yes, I know what it sounds like... one time got a bad tank of gas and it sounded like rocks hitting the exhaust shield any time I went WOT).
The wideband always shows/logs at least 11.5 AFR or lower during WOT, so I don't think it's a fueling issue. Mike @ Rev, says the delayed enrichment until ~5 PSI is ok and done for fuel savings.
Could something mechanically be broken in the engine, which only becomes an issue while on boost? I ask, because this is the same engine I swapped from the TW I wrecked (slid it over a curb and into trees). If so, what?
The car otherwise drives and performs fine. No CELs. Gas mileage is ~19-21 for mixed city/highway. Starts and idling is solid. I've got all this money/parts into it, but they're all pointless since the damn ECU stays in limp mode.
I'm basically out of ideas on what can be done to further troubleshoot this issue.
Since my last set of posts, I have:
* gotten the injectors cleaned and flow tested (434cc)
* received an updated Stage 2 chip (v3) which is programmed for 434cc and a sooner fuel enrichment.
* Re-installed the MBC and lowered boost to ~10 PSI.
* bought/installed another OEM knock sensor
* re-wired the knock sensor using microphone wire from the engine bay to the ECU. Connections are soldered, headshrinked, wrapped in electrical tape and automotive conduit.
I'm convinced now that everything related to the knock sensor circuit is functioning properly.
With data logging (either with Revscan or EvoScan), I can see that knocking is STILL a problem. The frustrating/confusing thing is that it's not constant. Some times, a WOT run will have the 'knock retardation' parameter logging up to 15* BTDC, other times it'll only be in the 1-2* range and some times ZERO retardation is logged. Knock retardation is ONLY logged while on boost, so it's not like I have something randomly banging around in the engine bay.
Mike @ Revtronix says that a few degrees of retardation, I should be actually hearing the engine pinging, yet I never do ever (yes, I know what it sounds like... one time got a bad tank of gas and it sounded like rocks hitting the exhaust shield any time I went WOT).
The wideband always shows/logs at least 11.5 AFR or lower during WOT, so I don't think it's a fueling issue. Mike @ Rev, says the delayed enrichment until ~5 PSI is ok and done for fuel savings.
Could something mechanically be broken in the engine, which only becomes an issue while on boost? I ask, because this is the same engine I swapped from the TW I wrecked (slid it over a curb and into trees). If so, what?
The car otherwise drives and performs fine. No CELs. Gas mileage is ~19-21 for mixed city/highway. Starts and idling is solid. I've got all this money/parts into it, but they're all pointless since the damn ECU stays in limp mode.
I'm basically out of ideas on what can be done to further troubleshoot this issue.
'11 WRX Limited
'94 SS | 3" TBE, 07 TMIC, TD05H-16G, Revtronix Stage 2, Walbro -- Sold
'94 TW | R.I.P.