Code P0101 Mass Air Flow troubles !

[jeff keyuk]

Took car out to get fuel 94octain,Car was running real nice!Next day went with the car, service light came on ,then car fell on it face! Fuel trims seem to cut back. So went back,check code!! P0101Mass air flow came up, went over the whole car, check for vac.leaks, check fues ok! Check grounds,even change the mass air ,same!Check Map senors and even put in a new one, still the same,my question is can bad gas set a P0101 code???

[jeff keyuk]

ttt

[joecar]

No... the MAF sensor and/or its wiring failed.

[jeff keyuk]

Hey joe! Nice to hear from you! I put in my other maf sensor and did the same thing, even change to new map sensor! What do you mean wiring failed??
I check for power going to the mass air and there 12 volts. I am going to post a screen shot of my VE table, Numbers in the low range seem very low!

[jeff keyuk]

http://img844.imageshack.us/img844/5664/programmanager20130603b.png (http://imageshack.us/photo/my-images/844/programmanager20130603b.png/)

[Rich Z]

Man, if my VE table is supposed to look even close to yours, I'm seriously way behind the curve in figuring out this tuning stuff.....

[slows10]

That ve table has to take the cake right there. No offense but that one is scary. Its not just the low areas but the rest of it makes no sense either. Did the car seem to run well with that? Can you post that same screen shot but with the 3d view as well?

[jeff keyuk]

Thanks! table went strange, I work it out, back on track!

[joecar]

Hi Jeff,

I'm fine, glad to see you can take the car out now that winter is gone.


Your VE table does not make sense as Rich and slows noted above... can you post your tune file...

are you running boost...?

if so do you have a 2-bar sensor (VE/MAF tables scaled, or are you running a COS)...?



Before proceeding it pays to visually inspect the MAF wiring for any physical problems, as you have done;

then have a read of this (see Conditions for Setting the DTC): P0101 (http://www.gearchatter.com/viewtopic10261.php)

if the VE table is off by a lot, then the PCM is calculating that the MAF table makes no sense...

[jeff keyuk]

Hi Joe! I went back to the stock B0101 & B0103 tables, Car running much better ! No more P0101 code! Cars LTFT were getting better,car was running better and I felt the IDLE was also getting better,So started back with VE tuning,I think were I screw up is when I connect to the car .The program ask if I want to connect to a nother ECU not my 97/98 ECU and did not noticing it, The table go screw up, Would that sound wright. I more thing There is 2 codes came up last night High and low responce to the o2's, should I leave that table stock for know until I finish with the calca VE tuning. or set the table now to ALL to 450mv.????

[jeff keyuk]

ttt.

[jeff keyuk]

Hello!!!!!!

[joecar]

Hi Jeff,

sorry, I somehow missed this thread...

oh, your Vette is a 97/98...?

what are you mods...?

if your VE tables being back to stock fixes the problem, then go ahead and do VE tuning but pay attention to how much the tables differ with each successive iteration...

I don't remember:
- do you have FlashScan V1 or V2...?
- which wideband do you have...?

[jeff keyuk]

Hey Joe ! I am, doing a calc VE tuning, I did the AutoVE Tuning first, I have a V2 with a fast WB, Mods, are 215ETHeads ,, Fast Intake92mm,90mmTB,Cam228/230,600/610Lift w/112lsa,Vera ram air duct, stock Mass air, Every thing was going good with the tuning, Idle started to come around AFR was getting better and LTFT were coming down! I think were I went wrong, is when I connect to the car with the scan tool, some times it ask with ECU to connect with, and instead of connect with the 97/98ECU I connect with 99/2000ECU, That's when the VE table went strange?? After going back with the stock VE table ,car is running much better, No B0101 code, But I am getting a fast response and slow response codes to the 02's now! Should I change the switching table to all 450mv??? Thanks jeff !

[jeff keyuk]

ttt

[joecar]

Hi Jeff,

Yes, selecting the wrong PCM would have resulted in some strange data on the scantool (I believe the tunetool won't flash if the PCM does not agree).

Yes, set the switch points to 450mV and see what happens.

You should be able to do several passes of Calc.VET to get VE and MAF fairly close... don't forget to copy B0101 to B0103;

[ do Calc.VET with the modifications for DAT (dynamic air temperature) for your PCM, and use the WO2BEN pid modified for your wideband ]

then do idle tuning;

then do AutoVE.

[jeff keyuk]

Hey Joe ! Thanks, Flashing a tune with the tuning tool is ok to 97/98 PCM, Its was when I started the scantool to make a connections, I have to make sure it connects to the 97/98 ECU if not it goes to 99/2003 ecu. Last summer I started tuning doing AutoVE tuning. Last summer you also sent me all the pids and custom pids that I am using. What coloum should I be watching to settle in to the LTFT. ( Avg.or mim)??? Also ! AFR at a steady speed of 3000rpm its 12.9 to 13.2 take my foot off the petal and coast AFR Drops to 10.0 that's going rich not lean, wright?

[joecar]

On the scantool Data tab, he LTFT column is the Data column (i.e. watch the actual value).

At steady speed of 3000 rpm at load AFR 12.9-13.2 is ok (but not a cruise, it's too rich for low-load).... and then it drops to AFR 10.0, that is going rich on decel (check VE table, and enable DFCO).

[jeff keyuk]

hey Joe! I check back on VE table b0101, I notice the low RPM cells 400 /15MapKpa and 800RPM/15MapKPA started to go down,so I smooth around the tables and brought them back up a little, Drop tune back in the car motor seem very chrisp!On enable DFCO which table do I adjust,there are 5 tables,
Paramaters B3313
DFCO Vehicle Speed enable
DFCO Throttle enable
DFCO RPM
What is the deal behind the DFCO enable??? Thanks again for all your help!
DFCO Map B3320

[joecar]

DFCO = decel fuel cut off (i.e. when you let throttle go closed (enabled based on those tables you mention, M6 tables are for M6 only, the non-M6 are for AT)...


DFCO enabled during tuning causes VE table to go down in that area...

when you're finished tuning, compare car decel behavior with/without DFCO, see if you like it enabled or disabled.


Look at your stock file to see how it is enabled.