02's,Trims,AFR gone whacky

[DenverPala1]

Hi all. Been having an issue lately. Tuning VE and MAF was going good till this started happening intermittantly. After a part throttle accel my 02's will flatline in the 900's, trims go way +++++, and my LM-1 shows a steadily richening condition. If I shift into neutral the problem will eventually correct as well shutting down and restarting engine. It only happens at part throttle. I reset my VE table to stock and my MAF table to an LQ4(running a Northstar TB)stock MAF table. After doing this it ran pretty good without this issue. So this morning I was driving around, unplugged my MAF to retune the VE table and all was going good until a part-throttle accel and then it started again. Here is three scans. The first is before I reset the forementioned tables. The second is from after resetting tables and it running decent, and the third from this morning when the problem cropped again. Any ideas on what could be causing this?

1st-http://denverpala.com/impala0404pmbad.hpl

2nd- http://denverpala.com/impala0405pmgood.hpl

3rd- http://denverpala.com/impala0406ambad.hpl

[DenverPala1]

Anyone? Any ideas or suggestions would be greatly appreciated. Ive tried everything I could possibly think of.

[Bill@HPTuners]

so the maf is unplugged in all theses scans?

[DenverPala1]

Actually no. It is plugged in those particular scans. However I went driving the vehicle this morning with the MAF unplugged because I was trying to do some VE tuning and it started happening again. So it will do this it seems with or without the MAF plugged in.

[Bill@HPTuners]

wonder why that is...have you thought about logging commanded a/f and maybe taking some of the useless stuff off of your table display? Normally the maf will try to keep you at 14.7:1 at all times unless youve fucked with the wrong tables er something...mind posting your bin file as well as your stocker so we can see what you changed & by how much? its as easy as using the file manager when you hit post reply and use up some of hpt's servers

[DenverPala1]

Thanks for the help. Sorry about all the useless stuff in my scans. Ill definately clean it up as well as add commanded AFR for the next posts. Here is the original and current bin files, as well as an idle scan from earlier this morning. Its not very good, I was turning the car on and off a couple of times because my 02's and LM-1 AFR meter were showing very weird stuff. Im running a ZZP XPZ cam, Northstar Throttle Body, modified heads, LQ4 MAF table, 60# Mototron injectors and no CAT among other things if any of that has any bearing on reading my scans. When Im trying to VE tune Ive got the high octane tables pasted into my low octane tables. I got a brand new stock 02 sensor. Let me know if I can provide any more info. I'll try to post up another scan while driving with the commanded AFR as soon as possible.

[Bill@HPTuners]

fwiw i dont think tuning your ve table is very useful for 3.8's because from my understanding its not used for part throttle. Im thinking those mototrons are what is giving you problems at this point and are probably overkill though you dont go wot in your scans so I couldnt tell where your IDC stands at. Thats the only thing that really stands out to me...other then in frame 14476 of the 3rd scan your a/f goes form 14.7 down to 12.7:1 just sitting at idle basically unless maybe you turned the car off or something

[Russ K]

Is that last scan with the new O2 sensor? If so are you getting any O2 codes?
Maybe the fuse for the O2 heater is blown as by the scan that O2 sensor looks
asleep.
HP Tuners told me along time ago not to change the ve on V6 cars. They said there are alot of differences from the V8 vehicles. So I would put the ve table back to stock and tune with the maf table.

Russ Kemp

[DenverPala1]

Ok. Ill change my VE back to stock and just try the MAF tuning. I have thought the same about my injectors but that is what a vendor recomended so that is what I got. I might try my stockers(36#) with their tables and see if that helps. Or just get some 42#'ers.

[mtcrusan]

Ok. Ill change my VE back to stock and just try the MAF tuning. I have thought the same about my injectors but that is what a vendor recomended so that is what I got. I might try my stockers(36#) with their tables and see if that helps. Or just get some 42#'ers.

When your doing the MAF tuning on our V6's.

Do you still need to change your PE table to 100 and copy your HO Table to your LO Table since we won't be in "SD" mode?

When calibrating the MAF would we find the averages of the MAF Hz and scale the MAF curve this way?

I am assuming that if you scaale the MAF more positive it will go leaner or am I assuming wrong?

I'm trying to understand this a bit more. I hope this will help everyone some.

[never0101]

I am assuming that if you scaale the MAF more positive it will go leaner or am I assuming wrong?

I'm trying to understand this a bit more. I hope this will help everyone some.

the way i understand it, if you scale the maf positive, you'll be telling the computer that more AIR is entering the engine, so it will compensate by adding more fuel. so bigger maf numbers = richer condition.