tuning frs maf/injector

[QTR FMS]

Originally Posted by Tor

What makes this difficult is that you are not very specific about where you see which values. Again, a log of a WOT pull is worth more than a thousand words.

When you say:



You mean like this (as a pattern, here the extremes are not really too bad because I start with a MAF scale that I know will roughly fit):





No, but you can adjust load without affecting MAF.


Assuming that your problem is just a bumpy AFR curve like above and that you don't actually see 13.8 or 12.9 ALL throughout the pull (if that's the case you have a hardware issue)....

Then the way to do it is:

1) You need a well scaled MAF first. The MAF should not be used to clear the bumps in the WOT AFR curve. It should average them out while the MAF remains a smooth exponential curve.

2) Clear out the bumps in the AFR curve using engine load compensation.

Engine Load Compensation should NOT be used as a means to skip step 1 and make a properly scaled MAF, to begin with.

If the above scenario is your case... Take a few steps back, restore everything regarding the injector back to stock. Use an unmolested MAF scale, like from the OFT tunes. (A bumpy MAF is only harder to make smooth again and, hence, a bad starting point).

Make a full MAF scaling and do not apply any open loop corrections below 3 volts. Make sure that the MAF curve remains smooth and averages out bumps. Do not make bumps in the curve between 2 and 3 volts especially as this will mess up your fuel trims. While doing this try to keep the curve within +/-2% fuel error in CL. Do not make a bump in the transition between <3 volt and >3 volts. In fact, do not make any bump in the curve at all. (Did I say no bumps!).

After that make logs again and this time apply the corrections to the engine load compensation table. Closed loop corrections below 0.8 manifold pressure. And OL corrections above 0.8.

Same car as the screenshot above after MAF scaling and 1 adjustment to ELC (can still be improved a bit):




The problem with all the above is that it takes experience (or a lot of trial and error). The UEL headers of the JDL, Tomei or Gruppe-S design are a bit tricky to tune. They make weird stuff happen to the AFR in the midrange that you need to know how to compensate for.

i honestly wish i could get my wot log as good as the first graph it look way nicer than my datalog, i have added 15% more fuel on transient and as i step on throttle i get 13.8 then 11.98 then 13.6 then 11.2 then 12.1 then 12.8 so its random the swing is larger than 4% and i cant get it close enough to ignore it

[QTR FMS]

https://datazap.me/u/fahad-alali/log...0&data=7-25-42
this is an old delicious tuning datalog
https://datazap.me/u/fahad-alali/log...&data=23-24-29
this is pi only you can see fuel cut at first wot
https://datazap.me/u/fahad-alali/log...?log=0&data=25
this is di only same maf scale stock injectors scale

[Tor]

Originally Posted by QTR FMS

i honestly wish i could get my wot log as good as the first graph it look way nicer than my datalog, i have added 15% more fuel on transient and as i step on throttle i get 13.8 then 11.98 then 13.6 then 11.2 then 12.1 then 12.8 so its random the swing is larger than 4% and i cant get it close enough to ignore it

It shouldn't be necessary to make all these changes to a near stock car. If it's too lean on getting on the throttle at low rpm, it's more likely that the load limits are wrong.

The MAF values at high rpm in the delicious log are too low with 120 g/s. Whether, it's a sensor issue or a tune issue.

Same car as in the other screenshots (running Gruppe-S header):



Another car with Gruppe-S header (my own):

[QTR FMS]

Originally Posted by Tor

It shouldn't be necessary to make all these changes to a near stock car. If it's too lean on getting on the throttle at low rpm, it's more likely that the load limits are wrong.

The MAF values at high rpm in the delicious log are too low with 120 g/s. Whether, it's a sensor issue or a tune issue.

Same car as in the other screenshots (running Gruppe-S header):



Another car with Gruppe-S header (my own):

do you think the maf sensor might be the issue?

[Tor]

Originally Posted by QTR FMS

do you think the maf sensor might be the issue?

I see you added two more logs in the post above.

Well, the sensor appears to be working. It's not leveling off like it won't read higher. Also it reads fine in your own logs - 132 g/s at 6500 rpm seems like a reasonable value. So no, I think it's a MAF scaling issue.

Going back to your previous post:

Originally Posted by QTR FMS

this is my maf scale from 4 months ago this is with stock injector value, it got my afr with 2%+- at wot , but now i tried it again and i got fuel cut at 6800

With fuel cut, do you mean when running PI only, as in maxed out? Unfortunately, it didn't log injection time correctly (a lot of other stuff it didn't log either). Neither did you select to log quantity. So it's a bit hard to say what's actually going on.

Do you have a log running on that scale running both PI and DI?

[Tor]

One of your logs was without the AVCS being active:

https://datazap.me/u/fahad-alali/log...zoom=9464-9700

If you scaled injectors based on a log with inactive AVCS, it's going to have messed things up.

Don't forget to let the AVCS activate before you do any logging:

[ame]https://www.youtube.com/watch?v=oGUOXcYrn8A[/ame]

[tomm.brz]

i see no fuel cut, what you mean is just the normal fuel cut as no throttle in, afr goes up to 20 and indicates that you have your foot out of the pedal acc and no fuel is injecte
you have 7% of PI at high rpm, you can t max out injector, i didnt maxed out stck injector while supercharged and 40% of PI

[QTR FMS]

Originally Posted by Tor

One of your logs was without the AVCS being active:

https://datazap.me/u/fahad-alali/log...zoom=9464-9700

If you scaled injectors based on a log with inactive AVCS, it's going to have messed things up.

Don't forget to let the AVCS activate before you do any logging:

i forgot to wait for avcs to activate, it takes to long to activate is there any way to speed up the process

[QTR FMS]

Originally Posted by tomm.brz

i see no fuel cut, what you mean is just the normal fuel cut as no throttle in, afr goes up to 20 and indicates that you have your foot out of the pedal acc and no fuel is injecte
you have 7% of PI at high rpm, you can t max out injector, i didnt maxed out stck injector while supercharged and 40% of PI

https://datazap.me/u/fahad-alali/log...5739-5733-5745
i have highlighted the fuel cut in this link

[steve99]

Originally Posted by QTR FMS

https://datazap.me/u/fahad-alali/log...5739-5733-5745
i have highlighted the fuel cut in this link

your port and direct injection open times are logging as zero in that log, something not correct with logging

If you running petrol on stock injectors and intake, NA, just load in a completly stock petrol tune and then you will be able to start diagnosing what happening.

dont change anything in tune use stock maf pi/di fueling, i think your just confusing yourself with all your changes.

no way your going to max out fueling even on E85 NA, ive run it for years no issues.

you very likely have a hardware problem.

start from stock tune, diagnose then fix the problem then move on.

[Kodename47]

Originally Posted by Tor

With fuel cut, do you mean when running PI only, as in maxed out?

I can't confirm but I would expect the OEM PIs to max out before hitting the upper RPM. It's not fuel cut but lack of fueling capacity.

Originally Posted by steve99

your port and direct injection open times are logging as zero in that log, something not correct with logging

He's logging in seconds rather than ms. That doesn't help matters.

[steve99]

Originally Posted by Kodename47

I can't confirm but I would expect the OEM PIs to max out before hitting the upper RPM. It's not fuel cut but lack of fueling capacity.

He's logging in seconds rather than ms. That doesn't help matters.

Yeah didnt even realise logging injector times in seconds not milliseconds was an option :-)


I don't think runnong 100% port would be good for the direct injectors either as being in combustion chamber i would think that running fuel through them would keep them cool, id be concered about damage with zero di fueling


Also strange that fuel system status logging 0 as well as stft and ltft and ecutek closed loop 0

[tomm.brz]

There is a ecutek bug in some roms for example in A02G when racerom v10 is installed, fu el system status will show 0 no matter what

ltft at 0 i guess he zeroed out the 2 long term min max, stft at 0 is strange maybe he zeroed the 2 af #1 correction min/max

[Kodename47]

Originally Posted by steve99

Yeah didnt even realise logging injector times in seconds not milliseconds was an option :-)

More recent ProECU updates allow you to change logging parameter values (seconds, F/C, km/h /mph etc) like ECU Connect does.

Originally Posted by tomm.brz

There is a ecutek bug in some roms for example in A02G when racerom v10 is installed, fuel system status will show 0 no matter what

That's rectified on v10.1, or it is on the A01G.