Cricket99SS

Couple issues going on. Car is a 1994 Camaro roadrace/auto-x car with a 99 LS1, TR224 on a 112LSA. Stage II heads, headers, intake, etc.

Started following the standard tuning practice, unplugged the MAF, reset my fuel trims, and headed out to log. I ended up with a sea of green numbers, most every value on the upper left 1/4 of the table at -12 or more.

I subtracted values and 4 trips later I end up with this.




First, how on earth is this engine running (and it pulls great) with this VE table and in open loop mode with the MAF unplugged? I have ZEROS in some places on the table, yet my LTFTs are still negative showing it's rich. I'm not sure how the engine runs in that section of the table, but it still runs great! I'm not sure how I can take more fuel away from that section.

Second, since the day of the first log, primarily the upper left section of the VE table contained large negative values. The rest of the VE table has always been 0 or barely positve from day one. I have subtracted 12 from just about each cell in the upper left section 4 times, and still cannot lean this section out! Why would just this section be pig rich and the rest not too bad?

Also, if I don't reset my LTFTs before I drive the car, as soon as I barely touch the gas, it shoots the idle to almost 3,000 rpm for around 20 seconds before it comes back down. When driving it stays at a constant 2,700-3,000 rpm, pulling you along. However I can pull over, reset my fuel trims via the HPTuners scanner, and it will idle fine at 700 rpm for the entire drive.

Anyway, it's late and I'm not sure what other info I should include. I am at a loss for words when looking at my VE table and understanding how the car is still running.

Any thoughts?

I have a good many free days here, so if any of you need more data, want me to try things, I can do them pretty quick and post back.

Thanks for the help.

SikHabibBroCuz

is the histogram being viewed with average values??? it might be set to min

Cricket99SS

Yeah those were average values, here are the minimum ones.

RedHardSupra

iTrader: (1)

did you actually unplug the maf (physically) or did you just disable it with 'fail frequency=0'?

Cricket99SS

I physically unplugged the MAF.

One other thing, RedHardSupra, I have seen varying conflicts between the tuning "guides" and "tuning 101s" etc. Should I reset my LTFTs after each change to the VE table? Some say to leave them alone, others say to reset them via the scanner each time. I have been resetting them every time.

P Mack

iTrader: (6)

Try setting the fail frequency to 0 instead. Your car may think the maf is still plugged in and just reading 0. I'd think that'd make it run lean instead of rich, but might as well try it.

What fuel trim cell are you in when it's idling at 3000 rpm?

RedHardSupra

iTrader: (1)

reset trims between VE tunes, but FIRST do the MAF calibration, it really saves disappointments. look at all the posts of the 'i did my perfect tune i enable maf and car barely stumbles' that's what you get when your MAF has no clue what's it doing.

Another_User

Before we go any further...has your IFR table been changed at all?

Cricket99SS

No sir, and I have also been resetting the fuel trims before I go driving also.

TAQuickness

iTrader: (28)

It looks like you are editing the Primary VE Table. In SD mode, for a '99, you need to be editing the BackupVeTable. When the back up is correct, shoot me a PM. I have a spread sheet that will take the Backup VE and massage a new Primary VE for you.

Another_User

Good call.

Black02SS

iTrader: (36)

It appears also that you may be actually using the subtract/add function instead of the Multiply by %

Another_User

Has anybody figured out what your car will do in the event of a MAF and MAP failure yet?

P Mack

iTrader: (6)

If you go to engine diagnostics>general>calculated airflow vs tps vs rpm there's a table of something, but i think that's the max airflow error, not the airflow itself. That makes me think there's a hidden table of airflow vs tps &rpm somewhere.

Cricket99SS

Now this is confusing. No tuning guide around says there is anything different about the 99's. They all say to edit the Primary VE Percent vs. RPM vs. MAP table.

In what years do you need to edit the secondary table to make changes rather than the primary?

Thanks for the help everyone!

-Kyle

P Mack

iTrader: (6)

I have heard 98-00 run off the secondary table when mafless.

Another_User

Yeah. As far as I know, if you have the secondary, then it gets used when the MAF is unplugged. The later years just don't have the secondary. It is pretty lame...what a waste of code.

Black02SS

iTrader: (36)

Can you send me your tune before you adjusted it along with a log? I want to see exactly what is happening to your car.

Another_User

I'll look at it if you send me a copy too.

Cricket99SS

Ok here is my starting tune, the only changes from stock are the idle set to 700 and the rev limiter was raised to 7,200 a year ago by someone else with LS1edit. I also copied the high octane spark table to the low octane in this tune as well.

http://anomaloustechnology.com/temp/idle_change.bin

Here is the first log I did after changing the idle. I removed the MAF plug, reset the fuel trims, and headed out to drive.

http://anomaloustechnology.com/temp/...-ltftreset.hpl

Thanks for the help guys!