NefMoto

Hey,

I've run into the issue of running very rich (block 032 shows -1% at idle and -13% and -16% partial) with all of the tunes I've been trying and I wonder if a a high-flow fuel pump has any relation to pumping more fuel into the system.
The thing is I have an Aeromotive 340 fuel pump which by their description should flow 30% more fuel at the same pressure so if I am not mistaken there would be way more fuel sprayed by the injectors with this pump and a stock fuel pump at the same injector opening times?

Thanks for the input.

You have a FPR so pressure should be constant at 4 bar.
Check your pressure with a gauge.

It is possible your FPR or fuel return is inadequate/borked so that your actual pressure is going higher.

Not all pumps flow the same at the same fuel pressure. Its like comparing a k03 to a rs6 turbo. @ 20lbs of boost the rs6 turbo will have more flow compared to the k03 @ 20lbs. Same idea with the fuel pumps. You will need to tune for the specific fueling setup.

Everything you said in this post is wrong.

Wrong. If your FPR works good, you will never have more than 4bar at the inyectors. doesnt matter the fuel pump capabilities. Check the presure with a gauge to check if the FPR works good, then check your tune.

You are a little bit right but your conclusions are completely wrong.

It is true that pump's MAXIMUM flow differs between fuel pumps at a given pressure. "MAXIMUM" is the important word here. The pump always pumps at 100% of its flow at a current fuel rail pressure which is regulated by FPR installed in fuel rail. From there, the injectors dictate how much fuel is injected into cylinders and the rest of fuel is returned back to the fuel tank.

So long the fuel pump can flow enough for a given fuel rail pressure, it doesn't matter how much it actually can flow. If 100 l/h is needed and your pump does just that, 100 l/h or 1000 l/h, the system will not see any less or more fuel injected since the pressure will remain constant.

Now, you said that you tried numerous tunes and have the same problem. Are you injectos the same as the tune is using? The only reason I could think of why you could see much more at part throttle but almost perfect at idle completely incompatible tunes for your injectors' TVUB/KRKTE values. E.g. your injectors flow much more than KRKTE in tune indicates with large enough TVUB to mask this fact at idle... but rearing its ugly head in part throttle where KRKTE weighs much more in calculating fuel mass.

Assuming this is a turbo charged car , a boost leak will cause the trims to go south as well 

Well I am running brand new 630cc siemens deka IV injectors with a brand new set of primary o2s and 85mm maf. First we tought that my maf is on its way out so i tried with 2 other ones with no change. Then i replaced the o2 sensors to rule that out as well. Same results with both tony's base tune and berttos' file as well so it has to be hardware related. My FPR is regulating the system to 4.1-4.15 bar according to the gauge and I wonder if that would make much difference and give me about -10% partial values. Any ideas what else could it be, other than the return line being clogged?  :'(

No boost or vacuum leak at all. I pressure test the system every weekend...

Meh I constantly fail not to spam the forum, but I forgot to share the logs after the O2 swap and driving around for 30 km.

https://docs.google.com/spreadsheet/ccc?key=0AhrG40GHpr-hdF9KTlhUd0VQZ2N1NmJ2d3JDMk5MSXc

please post the original .csvs and/or ECUxPlot graphs

I've only have the block 032 and 033 logs at the moment of a 30km drive. I won't be able to do any ME7Logger logging until tomorrow because I blew one of my IC hoses off.

Okay I managed to do some logging with ME7Logger now which includes different WOT and cruising logs in different gears.
Please have a look.

Thanks

Please get a single 3rd gear pull from 2500 to redline WOT.. thanks

From what i can tell though, your fueling looks fine post trim (req afr vs o2 voltages) but it is hard to say w/o wideband logs.

All i can think of is your old fueling had issues.

I'd just pull 10% out of KRKTE or MLHFM and see what happens.

I've attached the requested WOT log. There is some cruising in the beginning because I am not able to connect ME7Logger to a running a engine.
Anyways my WOT AFR was 11ish all the way, and my LTFT's are 0.2% -8.6% -0.2% -11.7%.

What I noticed is that when i clear fuel trims, they go down to about -3% and then they suddenly drop down to -10% after a couple of minutes of driving, and Bank2 is always the one that starts to fall first and I guess it pulls the other Bank with itself? The other thing is that I think i have some misfires at really low rpms (<2000) and I am not sure if it is caused by the rich mixture itself or it is the cause of it (all coils and spark plugs are new). I also wonder if a small exhaust leak on bank2 before the primary O2s would make it read a lean mixture and then the ECU would compensate for it? But I guess in that case my idle trims would be rich as well.

More likely you have post maf intake leak.

The system has been pressure tested starting from the y pipe so you say my leak would be at the maf housing itself or at the accordian hose? Because after them it was holding 15 psi just fine.

Okay i've tested the MAF housing and the accordian hose as well and there are _no_ leaks in the system at all.

Then  move on, and just assume you had a bad fuel filter, fpr, or pump before.

If you aren't seeing problems, pull 10% out of KRKTE or MLHFM and call it a day.

Well the thing is that I replaced all of these parts so everything is brand new and I am running exactly the same setup as berTTos does and I've been communicating with him in the previous weeks and we can't figure out why I am running rich (i am at -14% now) on the same setup with the same file while he is at a -2% tops.

Perhaps he has a small boost leak, or a slightly different maf, or a different intake setup.... unless you are seeing significant fueling problems in your logs (or wideband), i'd just stop worrying about it :)

Allright, thanks :)

nyet,

I've did what you suggested and got about 7% off of KRKTE and it did not really make the situation better but in return it made the car shake like crazy with a good amount of misfires and the LTFTs still dropped. I've attached the VCDS log I managed to make and I did another pressure test which came out negative, except for the thing that my PCV valve which connects to the Y pipe is releasing a good amount of air (I guess that is normal because it releases fumes back to the Y pipe under boost?)

Thanks

Sorry for posting again but this is crazy! After posting the log from my car I reflashed the original file w/o the KRKTE modification while the engine was warm and did a ride again,
and now my LTFTs are sitting at -3.1% at both sides for partial and -0.8 and -2% idle. Can someone really explain what the f**k is going on? :)

LTFTs take 50-100 miles to really take effect.

You may need to log STFT at various loads; perhaps there is too much variance.

Also, you should cap the PCV before doing a pressure test.

finally, please dont bother with VCDS, and get me7l working..

I have ME7l working, i just don't know where to log LTFTs in there, I was not able to find the variables for that.

fra_w, Frao, and so on. You will see them clustered together in config file.

for STFTs and LTFTs I just watch vcds live, I generally don't log unless I'm fine tuning part throttle fueling

Well we have basically ruled everything out and I cannot find anything wrong the only thing that pops into my mind is the EVAP system. Euro cars do not have that, but the M box files have code for it,
and the only modification in my M box file for that is just CLALDPE zeroed to to avoid a DTC about it. Do you guys think that more should be done to totally code the EVAP system out, or do you guys think that the EVAP system should not affect fueling at all?
The only other thing that comes into my mind is that the tune I am using has been done for 94 octane fuel, but I am running 100 oct, so i wonder if the pulled timing for the low octane fuel would affect the LTFTs that much. ( I basically have 0 timing retard.

Thanks

evap shouldn't affect trims or fueling, and neither should octane..

So since lowering KRKTE did not solve the issue at all, can you give me any pointers what to do next?

start looking for patterns in your STFT..

are there particular high/lows spots at a given load/rpm point?

btw when doing this, be VERY gentle.

you want to be looking at stfts in steady state conditions (steady load, steady rpm)

you'll have to experiment with various gears and speeds to get a good spread.

rka_w and rka2_w need to be added to the *.ecu and *.cfg file. I'm 99% sure of the RAM address.

Long term fuel trims:

Idle
rka2_w 0x3823E6, 2, 0x0000, {%} , 1, 0, 0.046875, 0, {additive adaptive correction of the relative fuel amount Bank 2}
rka_w 0x3823E4, 2, 0x0000, {%} , 1, 0, 0.046875, 0, {additive adaptive correction of the relative fuel amount}

Part throttle
fra2_w ;{AdaptationPartialBank2} ; {multiplikative Gemischkorrektur der Gemischadaption (Word) Bank 2}
fra_w ;{AdaptationPartial} ; {multiplikative Gemischkorrektur der Gemischadaption (Word)}

Short Term FT's:
fr2_w
fr_w

Edit: The above information is for ME7.1 M box.

That's some great info, I will do some logging as well when I find the time for it. Last week we redid the soldering job of the Bosch to Hitachi MAF conversion cable and plug. We basically cut the long VAST conversion cable down to 4 cm and redid the soldering and we have added heat shielding for the soldered area as well and my LTFTs went down to -7%, which is still not perfect. I would have never tought that this would actually make it better, but it did  ???

And here is an me7l log file of a 100km drive which shows that my bank2 is often way richer than bank1 but then they are equal.