Need help with my lnf

[DoMiStIc_RuSh_06]

oh and here is a copy of my config and gms1 tune

Attachment 25383
Attachment 25384

[Iam Broke]

Looks like a stock stage tune, your fuel trims are still off 5.5% LTFT & if you aren't jacking off the pedal just off idle, you have a throttle issue.

[DoMiStIc_RuSh_06]

nope, i was taking it easy on the throttle. What do you recommend that i check or where do i start? Im open to suggestions Also are my ltfts and throttle issue related? or totally different culprits

[pantherqs]

if you aren't jacking off the pedal just off idle, you have a throttle issue.

Greatest post ever, btw.

[Iam Broke]

nope, i was taking it easy on the throttle. What do you recommend that i check or where do i start? Im open to suggestions Also are my ltfts and throttle issue related? or totally different culprits

I told you in an earlier post to multiply the entire MAF frequency table by 0.95 to get the LTFT's closer to zero. That'd be where I'd start.

The throttle issue is a different matter, clean the pot on the pedal like Term posted and see if it helps or get the dealership to replace it.

If you save your logs with a date code they will be easier to reference later. I use 09-28a, 09-28b, ect. Just a thought. In the tuning program there is a place under Edit, Calibration details where you can save notes on what you changed in the tune, believe me, you need to do this or you will lose where you are. I note in the text box Stock MAF X 0.95 as an example.

When changing the MAF freq for example I always go back to the stock one by setting compare = 0 with the stock file open as a compare. That way if you were at .95 on the maf & you want to go to .93 for instance, you will get a true 2% change from stock, not a compound change of what you already have changed. It keeps the shape of the MAF calibration curve more accurate. Just my 2 cents.

Greatest post ever, btw.

Sig material???

[DoMiStIc_RuSh_06]

I went and checked the thing on the gas pedal and it's not dirty.....infact it looks brand new. Going to the dealer tomorrow to get the new bpv put in... I'll keep you posted and possible relog.

[Iam Broke]

I wasn't talking about dust on the sensor case, it needs to be checked out electrically.

[DoMiStIc_RuSh_06]

I had the new bpv replaced and it didn't make a difference. I also put the stock intake back on with stock filter an my fuel trims stayed at -7 still and the were -7.8 with the kn an hour before that. So what the best way to check that peddle sensor out. Am I gonna have to take the whole assembly out....

Once I find out what's making my fuel trims so screwed, I'll attempt to get this fixed.

[DoMiStIc_RuSh_06]

Would it be possible that a bad purge solenoid would cause part of my issues or could a bad maf sensor be part of the problem

[DoMiStIc_RuSh_06]

Did a datalog tonight and my ltfts were at -9 then went to -7.8. Can't wait to go home on thanksgiving weekend to put the car back to stock and check for leaks.....

[Gimpster]

Its was my experience that both of my stock 09's were running pretty big negative fuel trims when I first put the scanner on them. I think my coupe was like -10, and I hadnt turned a wrench on it. This sedan was like -7... just the nature of the beast.

I'm still in Germany, but I can scan the peddle assy service manual pages for you... unless someone else here owns the service manuals. A bunch of those proceedures suck though because they want you to use the Tech2 or just have you swap parts in general. I've seen very little in the way of checking like the resistance of pot's and such.

[Iam Broke]

I'm old school so I'd just use an analog ohmmeter to check the pot to see if it was a dirty wiper in it.

[DoMiStIc_RuSh_06]

Its was my experience that both of my stock 09's were running pretty big negative fuel trims when I first put the scanner on them. I think my coupe was like -10, and I hadnt turned a wrench on it. This sedan was like -7... just the nature of the beast.

I'm still in Germany, but I can scan the peddle assy service manual pages for you... unless someone else here owns the service manuals. A bunch of those proceedures suck though because they want you to use the Tech2 or just have you swap parts in general. I've seen very little in the way of checking like the resistance of pot's and such.

So what your saying is that if i cant find any leaks, that i shoulkd just try to tune it out? is it even possible to tune this out?

from my understanding, the fuel trims are normally on the plus side with the tc. Term still thinks i have a boostleak. If i did have a boost leak, where else should i check besides the charge piping and intercooler?

[Gimpster]

Assuming you have nothing mechanically wrong with the car (boost leak, etc) yes by all means tune out any neg/pos trim.

All I was saying is that bone stock mechanically + stock tune, I was seeing a large negative LTFT skew on both of the 2009's I've owned and I know both of them were mechanically fine. Every car is different and so are the operating environments we all drive in.

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IAB,

Yah I'd also use my old trusty analog to check the peddle pot sweep.

The only bummer is from all the pictures I can find of the accelerator pedal on these cars.... good luck getting inside of it. It appears to be plastic welded shut at assembly. It also appears to have a 6 wire connector, so I'll have to dig through the manual and grab the pinouts.

All I was saying is the service manuals for the car give really no useful informaton like they used to. Like what range the pot should be in etc.

[Gimpster]

Oh, and have you made yourself a boost leak checking device? Most useful thing a turbocharged car owner can have in his/her toolbox you find leaks with those in the strangest places.

[DoMiStIc_RuSh_06]

Yeah I had one made for $10 lol....I'm gonna check that next weekend.....I pray I can get this fixed.....the dealership isn't helping out that's for damn sure

[DoMiStIc_RuSh_06]

Oh, and have you made yourself a boost leak checking device? Most useful thing a turbocharged car owner can have in his/her toolbox you find leaks with those in the strangest places.

Also, should I have to disconnect the Lower cp at the throttlebody and cap it off. Last time I tried it with the The lower cp connected to the tb, air was going into the engine cause I could hear a noise coming-out of the intake, plus I'd lose the air as soon as it hit the system

[Gimpster]

I've never removed any CP on any car I've tested, and you will lose air through the motor... more/less depending on the position of the cams but thats OK. I was taught long ago to remove the oil cap when doing a test, but I've also seen a lot of people who dont. You will hear/feel air coming out of the crank case if you do.

I have an air pressure regulator on my compressor and set it for 20-25psi maximum. I have gone 40-50 before, but that was on a diesel truck of my dads. You don't want to just hook up full strength shop air to the intake tract.... or bad things can happen I typically start at 5-10psi and work my way up. I do that to find the big/obvious stuff first. Like if you set for 5psi and can't hold that.... your car has an epic boost leak.

Most decent air compressors should be able to hold 20-25-30psi, which is more than enough to listen around for the leaks. Otherwise I've always just used a squirt bottle with 50/50 water and dish soap to find the little leaks on intercoolers and such.

You might actually make a leak on your car just to see what I mean.

[DoMiStIc_RuSh_06]

Ok thanks for the explanation.....it's alot
More clear now

[DoMiStIc_RuSh_06]

Would even a little leak cause the issue I'm having or would it have to be a big obvious leak?