When trying to autotune, I unplug MAF and AFR goes to 19-20:1 What's wrong?

[ArKay99]

I have a 99 C5. Mods in sig, added a Z06 MAF, flow-matched 30lb/hr SVO injectors. Running 2002 LS6 Z06 OS12221588.
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I have been having idle transition errors so it was suggested I go back to SD and re-tune from the beginning. I have set the car up to go into speed density as per the AutoTune tutorial but at first I didn't unplug the MAF. I just set it to failwith freq 0 and Limit 1. It would go into open loop as my fuel system status indicators show, and my AFR, although predictable showed a lot of very jagged peaks and valleys in my VE table and they would stay that way. I also noticed that my MAF frequency PID was registering frequency, although my gms/sec was 0. Since I am using a 3pin to 5pin adapter I decided today to leave the SD tune enables, i.e. disabling all the closed loop enablers as per the AutoTune VE tutorial, and unplug the MAF cable from my adapter harness. The IAT sensor is still connected, just the MAF is unplugged.
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When I did this my inital AFR from startup is around 12.5-13:1, but when the car exits the cranking state about 2 seconds later, my AFR goes through the roof all the way to lean on my meter, 19-20:1. I had my IFR table set to the proper values for the injectors but I dropped it by 20% in 10% increments with no difference. I also increased my VE table overall 20% in 10% increments with no change. What could be causing this? Any ideas would be greatly appreciated.

[ringram]

Your IFR should be set to what it calculates to.
Then its pretty much down to your VE table. Can you post your VE table up?
Have you compared it to some of the sample tunes?
Assuming your WB is working well and you have no exhaust leaks etc maybe you just need to add a stout amount to VE. To drop 20:1 to 14.7:1 needs almost 30% more VE to get it inline. Perhaps its that far out?

If you post up a pic of your table some of the other guys will be able to make a few comments on it.

You probably want to get it close to stoich at idle so you can then check your desired idle airflow.

[TAQuickness]

for some reason, the PCM likes to run lean for a few minutes in SD

just re-read your first post... I got it backwards....

[ArKay99]

Your IFR should be set to what it calculates to.
Then its pretty much down to your VE table. Can you post your VE table up?
Have you compared it to some of the sample tunes?
Assuming your WB is working well and you have no exhaust leaks etc maybe you just need to add a stout amount to VE. To drop 20:1 to 14.7:1 needs almost 30% more VE to get it inline. Perhaps its that far out?

If you post up a pic of your table some of the other guys will be able to make a few comments on it.

You probably want to get it close to stoich at idle so you can then check your desired idle airflow.
Here are my IFR table values as I calculated them.


Ford SVO 30lb/hr Injector Flow
Manifold Vac
kPa (lb/hr) (gs/sec) factor = 0.125997881
-------------------------------------------------------------------
0 34.64162706 4.36477160395225986
5 34.85752419 4.39197418484624139
10 35.07209232 4.41900931455637392
15 35.2853557 4.4458800485312717
20 35.49733784 4.47258934898111704
25 35.70806157 4.49914009243753317
30 35.91754903 4.52553506849360543
35 36.12582173 4.55177698736375413
40 36.33290055 4.57786847988373455
45 36.5388058 4.6038121050705098
50 36.74355721 4.62961034886227201
55 36.94717396 4.65526562789837876
60 37.14967471 4.68078029329928951
65 37.3510776 4.7061566306665656
70 37.55140031 4.73139686764274311
75 37.75066003 4.75650317013139643
80 37.9488735 4.7814776473370535
These are the values I calculated and put into the IFR table. These values are the flowed values that were provided to me in the box. I assumed 3 bar.
Ford SVO 30lb/hr actual measured injector flow
30.597 @43.5psi - 3bar

kPa (lb/hr) (gs/sec)
--------------------------------------------------------------------
0 35.33037237 4.45155205391247689
5 35.54005001 4.47797099240223668
10 35.74849784 4.50423497709648284
15 35.95573724 4.53034670295804559
20 36.16178900 4.55630878772568651
25 36.36667330 4.58212377497703523
30 36.57040975 4.60779413703707869
35 36.77301745 4.63332227774161610
40 36.97451495 4.65871053506442256
45 37.17492029 4.68396118361624761
50 37.37425105 4.70907643702320892
55 37.57252433 4.73405845019161978
60 37.76975679 4.75890932146580849
65 37.96596463 4.78363109468504507
70 38.16116368 4.80822576114528170
75 38.35536933 4.83269526147103593
80 38.54859660 4.85704148740239661

If I run the IFR table with those values in order for me to get the car to run somewhere around 14.7 I have to have my VE tables set like this:

http://download.paltalk.com/roger/VE_Table.JPG

I have my Desired Airflow set like this:

IN GEAR Grams/Sec
|---------------------------------
|-40 22.873047
|-28 21.190430
|-16 19.554688
|-4 18.016602
E|8 16.766602
C|20 16.098633
T|32 14.809570
|44 10.231445
|56 9.309570
|68 8.715820
|80 8.067383
|92 7.645508
|104 7.481445
|116 7.230469
|128 7.040039
|140 6.920898

With the MAF plugged in and the IFR to some value that gives me the AFR I want with this VE table the car runs fine, i.e. all fueling and AFR is what I want. The only problem is it stalls randomly. Also, I would like to remove the MAF, but I can't because something seems very out of cal.
Here is my VE table with the MAF plugged in.
http://download.paltalk.com/roger/VE_TableNormal.JPG

And here is the IFR table with values that keep my fueling in line.


Grams/Second
---------------------
0 4.007813
5 4.031250
10 4.062500
15 4.078125
20 4.093750
25 4.140625
30 4.148438
35 4.171875
40 4.187500
45 4.218750
50 4.226563
55 4.257813
60 4.281250
65 4.320313
70 4.343750
75 4.359375
80 4.390625
---------------------

I know this fueling is screwed up but I'm not sure what to make of all this.
I just installed a brand new fuel filter, regulator, and these brand new SVO's that replaced a set of flowmatched SVO's, and I checked my rail pressure to be 58psi and it was very solid and only fluctuated slightly when punching it.
Also the WBO2 is a very new PLX that we have used to tune another car almost identical to this one and that one is fine.
One other thing I would like to state is, when I have the MAF unplugged and have the ridiculously high values in the VE table, the car idles fine but every so often, about every 20 seconds or so, the idle dips and the AFR goes to around 15.5 briefly and the PCM 'catches' it and blips the throttle to keep it going. It's almost like the fuel has shut off. It exhibits this behaviour if I drop the VE table to the 'sane' values and drop the IFR table down to about 1/2 what it should be i.e 2.1 gs/sec at 0kPa and scaled from there to 80kPa in order to get the AFR ~14.7.
I'm lost on this one.

[Tordne]

The second VE looks more realistic. The one with max % of 221 doesn't seem right.

What make/model is your WBO2, and are you sure its calibrated all good?

Edit: just read more and see PLX. I have PLX and have found to be VERY good!!!

[Tordne]

Did you change any other Injector related tables - offset, small pulse adjust, default/min pulse width etc?

[ArKay99]

Did you change any other Injector related tables - offset, small pulse adjust, default/min pulse width etc?
I did. I changed the minimum injector pulse width and default minimum pulse width. I decreased them by 20%. It had no effect so I reset them to stock.

[Tordne]

If you want to email me the tune file and a log (log must be created with the supplied tune). Then I can take a look.

Cheers,

[ArKay99]

If you want to email me the tune file and a log (log must be created with the supplied tune). Then I can take a look.

Cheers,
Wow. That would be great. I'll have to do it tomorrow. I didn't create a log file with the tune the way it was it was so weird. I just shut it down, came in the house and posted this thread.
I'll run a log tomorrow so I don't wake the neighbors at midnight here. :rockon:

[Tordne]

No worries at all mate... I'll be at work tomorrow so I'll need something interesting to keep me going :) I live down in New Zealand BTW.

I also notice that you obviously use PuTTY and what looks to be WinSCP ;)

I'll see something from ya tomorrow - email address is in my profile.

[ArKay99]

No worries at all mate... I'll be at work tomorrow so I'll need something interesting to keep me going :) I live down in New Zealand BTW.

I also notice that you obviously use PuTTY and what looks to be WinSCP ;)

I'll see something from ya tomorrow - email address is in my profile.
Haha, you're quite observant and quite correct! I'm a software developer and used those tools to get the screenshots up to my companies web server. Good eye.

[Tordne]

I'm an IT Consultant and use those exact same tools every day, and also to develop and get content to my web servers (one of which I host the tune repository on) :)

[ArKay99]

I'm an IT Consultant and use those exact same tools every day, and also to develop and get content to my web servers (one of which I host the tune repository on) :)
Consultant... great work if you can get it. I have to show up at an office 4 days a week. At least I don't have to wear a suit. Nice job on the repository, it's a great asset.

[Tordne]

Consultant... great work if you can get it. I have to show up at an office 4 days a week. At least I don't have to wear a suit. Nice job on the repository, it's a great asset.

Now we're talking ;)

[ringram]

Could your map sensor be reading wrong? Like have you got a 2 bar map in there or something.

[ArKay99]

Could your map sensor be reading wrong? Like have you got a 2 bar map in there or something.
It sure seems like it doesn't it? The MAP is reading 50-52kPa at idle which seems ok for my cam, and it tracks ok. At key on I read ~102kPa and on extreme deceleration using the gears I have seen it go as low as 10kPa. It also seems to track the load and throttle properly. Also it is the original sensor that came in the car.
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There is one thing I thought about that I did that I didn't mention. I multplied my C6101 ETC Predicted Airflow table by 40% to avoid a P1514 DTC setting. And also the did the same to the C6102 Max Predicted MAF Flow. I don't imagine these tables would have anything to do with fueling, as I understand it they are for rationality diags. I did set a P1514 when they were left stock with all my mods when I tried to go SD the first time, that's why I bumped them.

[ArKay99]

I found the cause of this issue. I had set my MAF modes properly, but set all three DTC's to not report.:doh: I fixed it by setting P0103 to report on the first failure, but not to set a MIL. Sorry for getting all you guru's going on a problem I created for myself. :bash:
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This begs the question though. Is there a way to cause the MAF to fail but not report a DTC? If I go SD in the future I don't want to have to put the MAF back in and do a reflash to get me though inspection. Yes NJ has inspections.:mad:
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I'm back on track for the time being.

[TAQuickness]

set P0101, P0102, and P0103 to non-emmisions. That should get you thru inspection.

[Tordne]

I would be inclined to restore the stock injector tables, with the obvious exception of the Injector Flow Rate table.

I played with the Default and Minimum Pulse Width tables and found that they actually made a HUGE difference. I set both those tables back to the stock (in my tune anyway) 1.28 ms.

Good to hear tat it is looking better though :)

[joecar]

I had been following along scratching my head... good that you have the MAF[-less] sorted out;

also, I suggest you set the units of AFR and VE to EQ and g.K/kPa respectively.

[ArKay99]

I would be inclined to restore the stock injector tables, with the obvious exception of the Injector Flow Rate table.

I played with the Default and Minimum Pulse Width tables and found that they actually made a HUGE difference. I set both those tables back to the stock (in my tune anyway) 1.28 ms.

Good to hear tat it is looking better though :)
Done. I had left them in the tune I sent you, since they didn't seem to do much, at least in the state the PCM was in with the DTC's messed up