|
Title: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: Dobermann on October 06, 2011, 10:21:20 PM Hello i have a question about a Audi S4 2,7 BI Turbo
i have to tune this car with bigger Turbo and 630 ccm Injectors and VP44 fuel Pump the car runs now but i have the problem that the cars is running a little bit to rich how can i get down the fuel injection ?? i know many abyout this engines and i have tryed many but it runs always to rich and smells after fuel. i tryed KRKTE to set down !! this solves the idle problem !! car start normal !! but under full load at ca 5000 U/min it feels like a fuel cut !! the car is jerky i tryed massflow into air filling to set higher cars runs good without jerky only problem is the idle !! i musst press throttle to start the car !! what can i do ?? is there another possibillity to make it lean ?? thank you for answers best regards Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: nyet on October 07, 2011, 09:48:17 AM Post logs. Preferably using setzi's logger or ECUx.
Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: s-company on October 09, 2011, 07:50:22 AM do you use a lambda tool (innovate for example)?
did you get any fault codes? Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: judeisnotobscure on October 10, 2011, 01:38:46 AM try using kfkhfm to tweak idle and part throttle fuel trims.
make sure mlhfm for your maf sensor is scaled to the proper housing size. set krkte to allow proper wot fueling and tweak kfkhfm for fuel trims, this is the best method i've found. Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: rob.mwpropane on October 10, 2011, 02:54:41 AM With 630cc injectors, I have read on here and elsewhere that idle is tough. Tony has stated trying to increase idle via "NLLM" maybe. Reply # 13 here:
http://nefariousmotorsports.com/forum/index.php/topic,34.0.html Hope that helps. Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: s5fourdoor on October 10, 2011, 09:36:10 AM try using kfkhfm to tweak idle and part throttle fuel trims. make sure mlhfm for your maf sensor is scaled to the proper housing size. set krkte to allow proper wot fueling and tweak kfkhfm for fuel trims, this is the best method i've found. jude: what equation do you use to scale the stock mlhfm? i've seen alot of uncertainty on this matter... Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: nyet on October 10, 2011, 09:51:47 AM Just scale it a fixed percentage until your load is where you want it.
Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: s5fourdoor on October 10, 2011, 09:59:15 AM Just scale it a fixed percentage until your load is where you want it. ok, so you had mentioned this before. just to confirm. you start with stock mlhfm. then you do a pull and log your MAF g/s. if the MAF reading gets above 350 g/s, you need to scale the mlhfm table due to the boundary uncertainty near the sensors voltage limit. the procedure would be to take mlhfm and set it to mlhfm * (1 + k) where k starts off to be say .01, stepping by .01, upto .25. in other words you multiple the entire table by a small fixed percentage and do pulls until your WOT g/s is comfortably below 350. is this correct? Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: nyet on October 10, 2011, 10:08:28 AM Not really.. the scaling doesn't help with the voltage limit - that is a function of the maf diameter and your intake set up. Put it this way: nothing you change in the ECU will alter the *voltage* the MAF is sending to the ECU.
All you are doing in changing what that voltage means to the ECU. In practice, i'd try to keep your max load under 200-220 (for k04s). alternately, you can set up your KRKTE to its theoretical value, and scale the MAF until your trims are near zero. Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: s5fourdoor on October 10, 2011, 10:23:48 AM i guess i'm failing to see where the load would come into the picture here. isn't max load governed by LDRXN? are you saying that when you measure actual load, if its pegging at the LDRXN specified value, then you need to scale your MAF up, so that "actual load" comes down below the max LDRXN value?
Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: nyet on October 10, 2011, 10:26:58 AM You are confusing actual load with desired load.
actual load (rl_w) is used just about everywhere in ME7. Most tables that use rl_w as an input have load axis that end at 191... Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: nyet on October 10, 2011, 11:18:58 AM Also, if you are worried about 'actual' load being higher than 'desired'.. that isn't really as much an issue as your relative torque being too high (i.e. load->KFMIOP * lambda correction * timing correction, etc).
The reason so many tuners ran underscaled MAFs for so long (IMO) was because ME7 was spending a lot of time intervening during part throttle, and the torque model is so hard to figure out, that the easiest thing was to keep MAF readings low. Basically, it isn't really LDRXN (rlmax) being too low vs rl you should be worried about, but rather KFMIOP being too high vs KFMIRL... Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: Rick on October 12, 2011, 05:47:08 AM I fixed his problem on, KRKTE wasn't calibrated properly.
Rick Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: Dobermann on November 02, 2011, 09:05:57 AM I fixed his problem on, KRKTE wasn't calibrated properly. Rick yes absolutly right !! problem is solved !! KRKTE was not calibrated right !! thank you rick for your help !! greetings from germany Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: TTQS on November 02, 2011, 12:04:33 PM yes absolutly right !! problem is solved !! KRKTE was not calibrated right !! Yet another person with issues caused by incorrect KRKTE... I'm losing count. ;) TTQS Title: Re: Audi S4 2.7 Bi Turbo problem 630 injectors Post by: judeisnotobscure on November 02, 2011, 01:41:27 PM try using kfkhfm to tweak idle and part throttle fuel trims. make sure mlhfm for your maf sensor is scaled to the proper housing size. set krkte to allow proper wot fueling and tweak kfkhfm for fuel trims, this is the best method i've found. jude: what equation do you use to scale the stock mlhfm? i've seen alot of uncertainty on this matter... i take the (new diameter)/ (old diameter) to get my correction factor and then i multiply mlhfm by that factor as a starting point. I have had to make very large adjustments to the scaling in some cases, especially when using a bosch maf. sometimes scaling seperate parts of the map up and down accordingly. |