Any ideas? Bucking and sputtering car.

[Super73]

Ok.. I’m at a loss here. Little back round.

Car is a 2000 Camaro with PRC 2.5 heads, Futral cam (230/232 on a 112), SVO 30’s, bolt ons. The guy put 600 miles on it with a stock tune and stock injectors. I swapped in the SVO’s last night.

Before I left his house I:
Set the idle to 1k
Changed the fans

When I got it back to my house, I started by following the programming for dummies thread http://hptuners.com/forum/showthread.php?t=3833 starting in the idle area.

IAC Park Position Airflow vs. IAT: Raise all points from -40C and up to 21
Idle airflow vs Engine Coolant Temp, all points 68C and up to 8.6
Primary VE 400*.6 – 800*.8 – 1200*.9
Coppied Low Octane to High Octane table

Took the car for a 5-10 mile ride and it ran fine. The LTFT’s were way off but I wasn’t too concerned with them knowing I was going to be making the next step when I got back to the shop.

I got back and then:
Set the Maf Frequency fail from 14k to 0
I reloaded the stock high octane spark map in to both the low and high areas
Reset the Fuel Trim Cells
Disconnected the maf
Went for a ride.

The car kept wanting to die. If I let it die, I would have to give it 25-50% throttle to get it to start. Acted as though it was flooding. Once driving, I got about 1 mile away from the house and it started sputtering bad. I mean real bad. If I tried to keep it at a constant RPM it would buck and sputter. If I cracked the throttle real quick, it would sputter, take off a little then buck and shutter again. I noticed the O2’s were jumping all over the place when this was going on.

I pulled over and plugged the Maf in. No change.

I pulled over again:
Reloaded the Maf setting to 14k
Plugged in the low octane setting

Car ran much better, still would sputter a touch. But very little. My laptop batterey was dying and did not want to get stranded so I headed straight back.


Is it normal for the car to turn to complete crap when trying to tune in SD?
Was it caused by clearing the Trim cells?

[Bill@HPTuners]

did you adjust the ifr for the change from 26lb to 30lb injectors?

[slow6]

when i changed my injector rate, the car would "buck" and go into LIMP mode.
it doesnt like weird numbers like: "22.27" so I changed it to "21.99"

[Bill@HPTuners]

when i changed my injector rate, the car would "buck" and go into LIMP mode.
it doesnt like weird numbers like: "22.27" so I changed it to "21.99"

not to hijack but isnt 22.27 stock in many v6's?

[S2H]

svo 30's are rated at 40 psi...
so your injector table would need to be

36.12542081    36.35056539    36.57432405    36.79672207    37.01778398    37.23753357    37.45599394    37.67318751    37.88913608    38.10386081    38.31738227    38.52972047    38.74089487    38.95092439    39.15982745    39.367622    39.57432548

then you should start by scaling down the lower half of the ve..basically below 2000 rom should be about -15~-30 %
and above should be richer by 15% and more up top...
its not uncommon to see #'s in your ve table reach 100+ up at 5000rpm and 85-95kpa...

your VE is going to be WAY off with all of that stuff..and until you get it close to in line its going toact exactly as you are seeing

[Super73]

Driveability went up for sure just scalling the whole inj flow rate. Still sputters down low but I'll try taking some more fuel away down there. Keeping it bellow 4k 50% throttle.

Full log: http://73-ls1.com/Tino.xls
Hisogram: http://73-ls1.com/VE_Histogram.xls

One thing I notice though are the LTFT's are way off from each other. Bank 1 is -15 or so and Bank 2 is upwards of +50

I have an extra set of O2 sensors from a Vette. Gonna try those.

[S2H]

can you just push up the scan file.....
.hpl

you can just attatch it here...

[Super73]

Help me out.. Where is Scan File?

[S2H]

when you log data...and you save the file...
before you export it....
I save all mine in a seperte directory, but its bound to be somewhere like program files->vcmsuite2.0->somewhere in there..LOL

[S2H]

oh...and if your bank 2 is going up to 50 like that..and resetting and doing it again...
there is something wrong with that o2...
possibly connected it to the rear one on accident instead of teh front one??
or bad o2 all together....

[Super73]

I haven't figured out how to save the log. I used to use A-tap and space bar would record it. Does HP tuners automatically save the info for you?

I think it might be one of the O2 sensors. There are no rear ones and using O2 sims for them. I'm tempted to delete them all together. But one less variable to change at this time. Might do it at a later date.

I swapped the O2's with the vette ones. The ones that came out were nice and black. When I put them in the header before they were white as a ghost, so I know the car was running real fat.


BTW, thanks for the info..

[S2H]

I haven't figured out how to save the log. I used to use A-tap and space bar would record it. Does HP tuners automatically save the info for you?

I think it might be one of the O2 sensors. There are no rear ones and using O2 sims for them. I'm tempted to delete them all together. But one less variable to change at this time. Might do it at a later date.

I swapped the O2's with the vette ones. The ones that came out were nice and black. When I put them in the header before they were white as a ghost, so I know the car was running real fat.


BTW, thanks for the info..

in version 2.0 there is an icon on the top bar that is right next to the section where you see a little play button/stop button combo....a little disk icon....
click it to save the file...its kind of around the middle of the entire bar...
theres one towards the left side as well..but its to save config file....dont use that one

[Super73]

Gotcha.. I'll hit that tomorrow before shutting down the car and post it up. Thanks again.

Think I should reset the LTFT's with the new O2 sensors?

[S2H]

yes reset fuel trims once your new sensor(s) are in

[slow6]

not to hijack but isnt 22.27 stock in many v6's?

not to hijack or get off topic but here is stock v6 3.8L:

20.39909, 20.39909, 20.33211, 20.26557, 20.20103, 20.20103, 20.34642 20.70440, 21.24912, 21.95222, 22.77104

so when max MAP is 100% its 22.27

EDIT: i changed mine to "21.99" across the board

[Super73]

Update..

Since I put in the new O2's last night, cleared the LTFT's things are looking much better. Average LTFT's are both in the -12 range.

I tried making some adjustments to the VE table and logged 31 minutes on the first ride and 29 minutes the second. It didn't seem as though the VE table got any better. I did clear the LTFT's again before the first ride.

Here is the log from the last ride http://73-ls1.com/Tino/tino4.hpl



Previous Tune http://73-ls1.com/Tino/previous_tune_no_VE_changes.hpt

Here is the file after the first VE change http://73-ls1.com/Tino/No_Maf_Scaled...PE_Changes.hpt

This is the one I'm about to upload http://73-ls1.com/Tino/No_Maf_Scaled...Changes_02.hpt

[S2H]

just so everybody knows....I have been talking with super73 on yahoo...
got him heading in the right direction..even after just me doing some file magic and 1 run...he is back on track..should be running swell in no time flat

[Super73]

To add to Scott's above post, I created a nice little excel spreadsheet some of you may want to play with.. http://73-ls1.com/misc/ve_conversion_2.xls

Open your current tune
Open last log
Drop in your Main VE from your tune (In red)
Drop in your secondary VE from your tune (In red)
Drop in your histogram info from your log (In red)

At the bottom you know have a new Main and Secondary VE (In blue).


I'll be putting a seconf portion up once I plug the MAF back in. Right now it is ploting your Main VE based on second VE since that is how the computer is working it.

The car is running pretty awesome right now. Idleing at 800. Every once in a rare while it will surge or die at a stop light, but rare. I have put a good 400 miles on the car in the last 3 days.

[S2H]

To add to Scott's above post, I created a nice little excel spreadsheet some of you may want to play with.. http://73-ls1.com/misc/ve_conversion_2.xls

Open your current tune
Open last log
Drop in your Main VE from your tune (In red)
Drop in your secondary VE from your tune (In red)
Drop in your histogram info from your log (In red)

At the bottom you know have a new Main and Secondary VE (In blue).


I'll be putting a seconf portion up once I plug the MAF back in. Right now it is ploting your Main VE based on second VE since that is how the computer is working it.

The car is running pretty awesome right now. Idleing at 800. Every once in a rare while it will surge or die at a stop light, but rare. I have put a good 400 miles on the car in the last 3 days.

except you need to do ut to 5 decimals

[Super73]

except you need to do ut to 5 decimals

Actually, the decimals are there.. The spreadsheet is just formated to only show you less. I can easily update that. But when you copy and paste, you are getting the 5 decimals.

I'll fix it to show the 5 decimals



Now, I have another question. What happens if I plug the Maf back in and set the fail to 14k?

Or if left in SD, what is the best way to tune on the dyno?
Does it go in to PE mode with SD?
What dictates PE mode? TPS / KPA / RPM delay?
TPS is reflecting the actual % of throttle? So 50 would be 50%, 75 = 75%?
With Hot Select PE being at 284, I'm assuming the HOT PE is the only table that will need to be edited for correct TPS reading?
EQ ratio vs RPM is the field I need to edit once on the dyno?

For spark:
Main spark table would be the place to edit?
.6v = 50% throttle?


Any more I should think about?

Just wont to make sure I understand fully.