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the LTV info builds up correctoins over time so best to check it after maybe 50 miles or so to see how things are looking.
To me this looks like a freshly reset car - your IAM value will start at 8 and work it's way up to 16. Once at 16 your using the full amount of timing the ECU is programmed for - this is like a self defence system for the ECU to protect against crap fuel. When it hears enough knock in enough cells it drops the IAM value and so kills timing across the board. The more IAM is reduced the more total timing is reduced.
You can get it to jump up to 16 fairly quickly (you can log IAM in romraider logger and watch it) - just used 2nd or 3rd gear and apply a little braking with your left foot whilst opening the throttle around 2500-2800rpm. Basically your trying to build boost without accelerating and the IAM should bounce up to the max 16 fairly quickly. After that if you do a pull and the IAM drops down it usually means something sup (poor fuel or engine issue).
You can see in the big table you have a negative value, this means the ECU heard knock and pulled back timing accordingly. Now - normally you wouldn't see any negative corrections until you get the IAM value up to max so that could be a sign of trouble. Further analysis would be needed on that one.
The A/F correction table builds up over time, this is basically how much fuel adjustment the ECU had to make whilst cruising to get your AFR back to what it should be. In open loop the car will always be trying to hit 14.5/14.7 - when it can't do that (which is 99.99% of the time) it makes a small correction to the airflow readings until the right figure is fed back from the front o2 sensor. On a stock car (stock airbox that is) you'd expect to see these figures around + or - 1 (or anything inbetween). On a "modded" car (panel filter/maaaayyyddd exhaust y0/intercooler etc.) you'd be looking closer to +/- 5 across the board.
As it stands your figures look fine, but you've not really covered enough distance to make them worthwhile, check it again after 1/2 tank of fuel and again when you top up and see how it's looking.
I think I may have an issue here, as I've never had the ECU reset and hasn't been in a garage for 4 months, so no battery disconnect I can think of. I usually use Tesco 99 fuel or at worse normal super unleaded.
Could the the reduced IAM also retard the boost levels too?
the IAM would have to drop much lower to start reducing the boost levels.
Take a 3rd or 4th gear log with the following items:
engine speed
vehicle speed
manifold relative pressure direct (psi)
target boost (psi)
primary wastegate duty cycle (%)
mass airflow (g/s)
engine load
feedback knock correction
fine learning knock correction
ignition total timing
IAM
A/F Sensor #1 (AFR)
any chance you can post those as CSV or Excel files? Helps for making graphs just
is it possible you logged absolute pressure rather than relative/corrected pressure? If that happened then the standard idle target of -0.15 psi would be 14ish (absolute pressure takes atmospheric pressure into account). If your atmospheric pressure was around 14.65 then take away the standard boost target of -0.15 and you'd be around 14.5ish which is what your seeing there.
yes but you logged target boost (PSI ABSOLUTE) so your boost targets all include atmospheric pressure.
Going by this log - it seems your IAM is still at a lower value and the car is knocking as you come on to boost around 7psi/2600rpm. It doesn't start adding timing back in until you get up to 3000rpm/12psi. What happened around 3800rpm/4100rpm - did you lift the throttle?
Knock on spool up could be a lot of things, check for any of the following:
crap fuel
air leaks/boost leaks/exhaust leaks
weak spark/bad earth
spark plugs
See how you get on from there, if you can't figure what it is then might be stuck having to go somewhere for a proper diagnosis. Sadly there's no app that's as useful as a trained eye and ear!
yes but you logged target boost (PSI ABSOLUTE) so your boost targets all include atmospheric pressure.
Going by this log - it seems your IAM is still at a lower value and the car is knocking as you come on to boost around 7psi/2600rpm. It doesn't start adding timing back in until you get up to 3000rpm/12psi. What happened around 3800rpm/4100rpm - did you lift the throttle?
Knock on spool up could be a lot of things, check for any of the following:
crap fuel
air leaks/boost leaks/exhaust leaks
weak spark/bad earth
spark plugs
See how you get on from there, if you can't figure what it is then might be stuck having to go somewhere for a proper diagnosis. Sadly there's no app that's as useful as a trained eye and ear!
Might have lifted the throttle - road wasn't that great.
Many thanks for the advice and tips - will look into those. Could a air/boost/exhaust leak cause the target boost to be 14.5 and not the 18 expected from a PPP?
the boost target is different at idle vs when your moving, it changes depending on RPM and throttle %. If you log target boost (psi relative), engine speed and throttle input you'll see it changing.
Air leaks wont change target boost, only a very low IAM (which would also drop you into safe fuel map). Your not that low yet so something mechanical is preventing you from hitting the target boost.
Ah, thanks, I'll do some more extensive logging to help with my understanding.
Re the boost - I'll check to see if the restrictor pill is in the right place over the weekend, otherwise might be a trip to the garage to see if they can find a leak somewhere. I had the actuator replaced last year.
the missing pill will only make your boost lower than it should be, if your knocking it's going to be because of bad fuel/bad spark/bad mixture so some investigation might still be needed.
A quick update - got my car back today after replacing the up-pipe (old one was at risk of breaking up a bit - precat) and the turbo (so much play in the old shaft that it wouldn't boost above 11psi). Managed to get a reconditioned TD04 from ebay. All fitted and now boosting as expected - what a difference!
Looks like my peak boost is now 1.4bar with the decat up-pipe. On doing a learning view tonight it looks like this:
Am I right in assuming that as the IAM is at 16 and there is no fine learning knock correction showing that it isn't running too lean and there's no knock present and all should be fine?
yes that learning view shot looks good, airflow corrections are minimal and no knock corrections have been saved.
that doesn't mean your not running too rich/lean on boost though as those corrections aren't saved by the ECU - that's where MAF scaling comes into play! It would be worth doing a few logging runs just to check the fine learning and feedback knock corrections aren't showing any hits too.
yes that learning view shot looks good, airflow corrections are minimal and no knock corrections have been saved.
that doesn't mean your not running too rich/lean on boost though as those corrections aren't saved by the ECU - that's where MAF scaling comes into play! It would be worth doing a few logging runs just to check the fine learning and feedback knock corrections aren't showing any hits too.
Many thanks.
All logging runs show the columns for fine learning and feedback knock corrections are all zero.
Am I right in assuming that even if it's running lean, given the learning view is fine, then nothing too damaging is happening? I don't tend to have the car at WOT that often anyway!
if its running really lean then it's damaging things - when it gets to the stage that it starts to pull timing you may already be too late as the damage has been done. If it's just a little over target boost but holding decent AFR's and the injectors aren't maxed out on duty then your most likely gonna be OK.
the standard sensor is desperately inaccurate on boost due to it being stuck up in the manifold so you can't always trust what it's telling you. 11.25 from the stock sensor could be anything richer than 11.25 as that's as low as it will read.
Generally tho if the car isn't too heavily modified and has a stock intake setup then you can be reasonably confident that your hitting your target AFR's from the primary open loop fuel table - at least it's showing you've got fuel on boost which some would consider "good enough". Personally I'd still say make a trip to a dyno just to have it checked on a proper wideband that will show you the true AFR throughout the pull and you can see how rich/lean you are.
Personally I'd still say make a trip to a dyno just to have it checked on a proper wideband that will show you the true AFR throughout the pull and you can see how rich/lean you are.
good call, I'll look to do that into the new year.
Yes, everything standard aside from the de-cat up-pipe. Probably should have just gone for a straight WRX up-pipe with pre-cat to avoid any issues, just that old second-hand ones didn't appeal and the STI up-pipes are easy to come by.
26 August 2015, 05:29 PM
I'll get checking 
good call, I'll look to do that into the new year.
