i need someone to take a look at my tuning file... ive compiled it from a buncha different files and tried tweaking it along the way myself! ive also included two datamaster files as well... one is a lil bit of WOT driving and the other is just normal closed loop driving....

in my WOT run youll notice that the left bank o2's are reading like 910mv and the right side is at like 860mv =/ this goes along with the BLMS in the next thing im gonna show you!

in the NORMAL DRIVING youll notice that at idle my left bank BLM's seem to be running rich so they are at like 113 but then the right side is at like 128?? then while just normally driving around the intergrators & BLMS seem to be BOTH below 128 which would indicate running rich and they are subtracting fuel =/ my ? is WHY? from what tables does the computer decide WHEN the car is running rich and lean?? what do i need to do to clear this up?

please note that these datamaster logs were made like 2 days ago, and i was also running straight race gas just to leave out any chance of detonation.. i also have my knock sensor completly bypassed just letting you know..

please lemme know what direction i should be heading in as far as handling the tuning on this!

thanks again!!

TUNERCAT TUNING FILE IM USING
DATAMASTER NORMAL DRIVING LOG
DATAMASTER WOT LOG

 

I don't think I'd be too concerned with that. Seems like most cars are slightly different from bank to bank. Age of O2 sensor, placement in the exhaust stream, some other little things can have an effect on that. My car is pretty much stock and both sides aren't dead nuts on either.


The computer decides it's runnig rich or lean based on O2 sensor input in closed loop. You're not actually running rich or lean. As long as the blm's are adjusting your fueling then the PCM is trying to maintain your 14.7:1 a/f ratio. So you're OK there.
If you want to screw with it a little you can play with injector constant a little. But be warned that this will also alter your idle and wot fueling. What is probably better is to play with the maf tables a little.

Does your car really want that much timing at wot? Seems like quite a bit.

 

Are you sure you dont have an exhaust leak on one side, I believe that could cause this as well.

Thx,
Claude

 

sounds like the norm to me for a guy with a decent sized cam.

 

Sure could. I was thinking that when watching the datalogs...but the low side isn't consistent, from what I remember.

 

an exhaust leak would cause the car to run lean though! where here with the blms being below 128 that would indicate rich??

i went back to the stock timing tables and ran vemaster & also lowered my inj constant so ill run some more logs and see how it comes out

 

I know I'm tired, but are you sure? If you have extra air that is getting into the exhaust before the O2 sensore then the O2 sensor is going to tell the ECM that the car is running lean and then the ECM will compensate by upping your blm in order to lengthen the injector pulsewidth...thus making the car run rich. That sound right?

Remember that just because your blm's are above or below 128 that doesn't mean that you're running rich or lean. The ECM is making it's corrections so that you keep your 14.7:1 a/f ratio at part throttle.
BLM below 128 means the ECM is lowering your pulsewidth in order to lean the car out to get your 14.7:1 and above 128 the ECM is adding fuel to try and get 14.7:1.

 

yup and i agree with you on how it works 100% but your contradicting yourself though your saying that if there was an exhaust leak that it would tell the ecm that the cat is running lean and that it should add fuel! well wouldnt that make the blm's go UP??? where in my case my BLMS are going DOWN??? PLEASE correct me if im wrong but i was thinking about what your saying but then like i said if it were an exhaust leak that should make the blms go up! thats the usual fix for guys that are running lean!

like i said i was thinking the same thing like if theres some kind of chain reaction like... i have an exhaust leak.. the o2's lean out... the ecm tries to correct and raise the blms... but so then why are mine LOWERING then

 

If you try the Injector adjustment and it does not work, then I would start looking for an exhaust leak on your right side (NOT the left). My car is doing this same exact thing right now. Its running rich to begin with 115 on the left block learn at cruising speeds but the right has an exhaust leak and is reading 123 and up. At WOT, my 02s look very similar to yours too. So do NOT rule out the exhaust leak (Mine is on the header flange, I believe the gasket is on its way out)

Once I get my exhaust leak fixed, I will have my car dyno tuned to get it running more effieciently and make more power.

Just trying to help,
Claude

 

im telling you everything is normal man! with a cam you create a lot of overlap at idle and especially so with 800 rpm or whatever it is you are idling at. this creates a lot of turbulance in the intake which pulls a/f mixes around which of course confuses the PCM into thinking one bank is rich and the other is lean. when you start to increase RPMs you decrease the amount of time the valves overlap which levels things out and then your split goes away. one thing you could do if this really bothers you is create a file which only goes into closed loop after 1000 rpms or somethin.. this will default the idle cell to 128/128 both sides forever basically.

 

How am I contradicting myself? What you just said is exactly right and is the same thing I said. BLM does not indicate whether you are running rich or lean. What they tell you is whether or not the computer is adding fuel or subtracting fuel in order to see 14.7:1. I think this is where you are getting confused. You're car is not running rich as long as the blm is correcting your pulsewidths.

Right, but go up from what? If you have an exhaust leak the PCM is going to raise your blm to try and correct for what it thinks is a lean conditon...therefore you will run rich since you really don't have a lean condition to begin with. It is possible that the PCM can add enough fuel and the blm would not go over 128.

Because you don't have an exhaust leak! You're dead right in your thinking that if you had a leak your blm would go up. I didn't dispute that. When I said "Sure could. I was thinking that when watching the datalogs...but the low side isn't consistent, from what I remember." I couldn't remember whether your blm's were above or below 128. I wasn't looking at the datalogs at that time. All I was saying was that an exhaust leak would split your blms. Whether or not the leak is bad enough to cause your blm to go over 128 depends. If the PCM file is set to run the car too rich and your blm's are down around 108 then on the side where you have a leak your blm could go up to 125 or whatever and the PCM would think that it's adding enough fuel to correct its percieved lean condition. You don't have to have a blm over 128 for the PCM to be correcting for a lean condition due to an exhaust leak. The side with the leak will just be higher than the other side. Now if the PCM was trying to correct for a true lean condition then the blm would go over 128.
Ok...I just watched the datalog again. I don't think that there is anything wrong there. As long as the blm is making its correction you're fine. I would say you might want to scale the maf a tiny bit or add a little to the injector constant and you should see your blm's come up to a range more centered on 128.

 

lol dude dont get me wrong.. im not tryin to be a dik or nething... your being VERY helpful

im not TOooo concerned with my part throttle its my WOT that im really concerned about... if you look at the WOT logs you notice that my LEFT BANK is Sooooo Farrr off from the right one! thats NEVER been like that before! out of all my years of looking at logs etc.. ive never seen it do that until now... youll notice that they are AT LEAST 40mv off almost ALL the time at WOT and they even go off as much as 60mV at some RPM's..... that CANT BE RIGHT!! so what is causing that then??

yea the blms tell you when the ecm is adding or subtracting fuel... which in turn would also tell you that if the ecm is SUBTRACTING fuel (BLMS BELOW 128) that would indicate that the car is running RICH... and if its ADDING FUEL (BLMS ABOVE 128) that would indicate that the car is running lean... am i right so far??



ok but my blms are below 128... so what would that indicate then?? see what im trying to say... if i had an exhaust leak and knowing that an exhaust leak would make the ecm THINK the car is lean... wouldnt that make the blms read ABOVE 128 indicating that the car is running LEAN and that the ECM is correcting for a lean condition by ADDING FUEL.... see what im getting at??


thanks for your help dan... your knowledge has been VERY helpful

 

If it were my car the first thing I'd do is swap the O2 sensors from side to side to rule out that the race gas is affecting one, or both.
If you need new O2's and plan to continue running the leaded stuff check out the O2's
here.
I just ordered one for the GN last night since I run straight 110 in it. There are some threads over at Turbo Buick,and it seems like they are holding up quite well to the leaded gas.

Edit: I don't know why I noticed this but when I posted this my post count was 666, so was yours!

 

LMAO holy sh*t... wtf is up with that thats frickin weird

well neways back on the sub.. i dont use leaded race gas in my car... never have... ive always run 104 unleaded... and BOTH of my o2's are like EXTREMELY NEW prolly only have less than 4k miles on them.... ill prolly just play around with the tuning file some more and see what happens...

 

Ahhh...I ASSumed when you said "race gas" you meant the good leaded stuff.

Not sure what else to tell you. I've got quite a few datalogs here from different cars and the O2's on both banks aren't always dead on with each other. It seems one side is usually 20-30mv lower.
Is the car running differently now than it was before you noticed this?
I really don't think it's anything.