MAF tune makes engine shut off

[LETZRIDE]

This is in a 1996 3.8L camaro with a 97 pcm. The car is N/A with a big cam 230/240 duration. Full head work etc.

I have been running a VE tune for the past couple of years, but would like to move back to a MAF tune. Ive picked up an LT1 MAF and installed it on the car.

So far I have been tuning cruise and havent gotten the car over 6000hz. Fueling is pretty good, I got it pretty close to 14.7ish under light throttle conditions, the problem is, when I let off the throttle to come to a stop, the car dies out and shuts off unless I two foot the brake and gas to keep it running.

If I flash back to the VE tune, the car acts perfectly fine...did I miss something?

Ive attached the MAF tune as well as two scans that end in the car killing itself when coming to a stop. It does this every time unless I two foot.

edited: took away my scan/tune...please see my newest stuff posted further down

[LETZRIDE]

just tried starting from scratch with a good tune I had back from 2009, still get the same result. Does anyone have any ideas? I'd like to get this MAF tune working

[LETZRIDE]

alright more food for thought:

I havent had a chance to go back out and I won't until Saturday now, but a few things come to mind. Right now back on my VE tune I notice (it always has, just dawned on me now) that when I come to a stop, I drop voltage- my car as it is now on the VE tune goes pretty quiet from its usual rumbling self, possibly indicating to me that it is on the verge of shutting itself off, just not quiet at that threshold.

With the MAF tune, does the voltage vs injectors tables come into play but maybe not when the MAF is set to fail? Could adjusting this table help me? if so, what/how do you adjust that table correctly?

[LETZRIDE]

seems like every v6 tuner has fallen off the face of the planet? Or am I that one guy who just discovered a problem that no one else in the v6 community has seen yet?

More information on the issue:

The car dies when you go forward even under 1-4% light throttle then hit the brake to stop. At this point the rpms dip down and the car chokes out and dies.
- The car does this regardless of being in open/closed loop
- idle maf calibration is now no more than 6% off in the relative HZ columns
- I dont believe AFR/rich/lean conditions to be the cause- in the scan you will see at teh moment the car dies, afr is as follows: 1054rpm- 13.99afr; 864 rpm- 14.11afr; 702rpm- 14.14afr; 604rpm- 14.08afr; 527rpm - 14.42afr; 431rpm- 14.94 afr and all the way down to 233rpm is at 14.64 afr.

So it's not a case of the car being wayy too lean or too rich when it is choking out...so what's the issue here? Like I said, I flash my VE tune back in and the car runs beautifully with the exception of the voltage dip I get while coming to a stop (which also happens with teh maf tune) but has been happening forever and is common.

whats the deal here guys? Im beyond stumped. I even tried making the voltage offset 1.0000 across the board- Nothing.

Attached below is the updated tune, last scan and my configuration file. Someone help me please.

[Overkill]

Revised the idle only portion of your maf curve, any better?

[LETZRIDE]

I'll let you know in a few minutes. I'm going to run out and toss this in the car right now. Thanks.

[LETZRIDE]

Revised the idle only portion of your maf curve, any better?

Fucking awesome...Where abouts are you in Toronto...I owe you a beer...seriously

explain to me though, if the AFR wasn't off, why does lowering those cells that you did make a difference? I always thought you take what your lowest cell was and fill in that same number into those bottom cells that you don't actually hit?

[Overkill]

Your MAF curve should be a smooth curve with the same slope going right down to zero.

I'm in Whitby. There's lots of things that I'd like to apply to your tune but I know you're very keen to DIY. I'm around though if you change your mind!

[LETZRIDE]

Your MAF curve should be a smooth curve with the same slope going right down to zero.

I'm in Whitby. There's lots of things that I'd like to apply to your tune but I know you're very keen to DIY. I'm around though if you change your mind!

Let me actually get this tune reworked/going so that it is good then I'll send it your way when I think it is complete. Then you can let me know if you still think you can pull some power out of the car and what your thoughts are as well as let me know pricing.

Is your shop located out in Whitby?

I appreciate your understanding of me doing things myself. I don't mind if we tweak things, so long as I am present/can see all changes that are made. I'm very hands on, so that when I encounter problems I know exactly what was done/wasn't done because I did it/was present and nothing is a surprise.

Do you have a dyno at the shop? I'll probably be looking to do some dyno tuning as the final touches on this tune.

Thanks for your help Will.

Mike