at my bin file? i burned around 20 chips in the last 2 days, but the engine still stumbles/backfires when i rev it over 3000rpm in closed loop. in open loop its doing better.

i have found the vortec sparktable in the forum here.

blms are at 128 all the time. o2 sensor shows around 1.000v when its in closed loop. sparkplugs are black. (too much fuel ? )

thanks,
nebu


Eprom

 

BLMs will be at 128 when you go into PE mode.

02 volts at 1v, means you are pegging the sensor, and black plugs, means you are VERY rich.

 

so what should i do? lower my fuel pressure/bpw constant?/ve tables?

Nebu.

 

Do you have larger than stock injectors?
What upgrades have you put on the car?
Do you have an AFPR?

 

upgrades are in the sig.

 

what FP are you running? i would think 12-13 lbs.
did you set you BPW in constants per the formula?
car i would think would run better that you are suggesting at 20 burns?
i assume you are data logging and correcting those VE tables first at idle and then up the scale b4 you do any hard running. i ended up putting in new plugs after getting the tables close. i too was very rich and was a new tuner...

 

dont know which FP. i raised the stock one a bit...
i have set the bpw constant to work with the bigger injectors.
i'll try to lower my VE tables some more. maybe that helps a bit.

Nebu.

 

i would set the FP to 12/13 no more. that is where mine is anyway(12). the cam is possibly adding more fuel as well down low. the BPW is set also by FP so there is an adjustment there in constants unless you are close to 12. work the VE fuel tables at idle off idle in driveway and up the scale. i seem to get more cells in wide average. eventually work the low speed driving VE. i like your self probably jumped in car day one and wanted it to go and it did not as my state of tune was compromised day one.

 

I hope you're not using the ecu file on TunerPro's website. He still hasn't replaced it with the new ecu file. The old one on that site displays the main VE incorrectly and will leave you scratching your head. I can tell you the changes to make in the ecu file to make it work correctly. The first step is to click on the "Main Fuel Table #1 % Volumetric Efficiency" under the tables subwindow. Press F2 to bring up the ecu edit. Under Columns put 8 and under Rows put 9. Next swap the Y Label (Units) and X Label (Units). Now under X Axis Labels start with cell 1 and put a 4, then 8, 12, 16, 20, 24, 28, 32 . This is RPM x100. It's limited to 3 Characters . Under Y Axis Labels start with 20 and go to 100 by 10 (cell 9 will have 100). That's the fix. I really wish it could be updated because I don't want people wondering why it isn't working when it's already a learning curve just figuring out how to put the 2 VE tables together for a complete 3d ve map.

As for the running rich. I'll e-mail you an eprom that should work much better and get you on the right track. Stock is great for stock but when tuning anything other than stock with a few bolt ons it becomes necessary to limit the control of the ecu over your engine. A perfect example of this is the way the VE tables are designed in the 350 TBI applications where the VE of the engine is less at higher manifold pressures. This is nearly impossible but the only time they ever go into those area's is when they're in need of some acceleration hence PE mode is evoked and those are plenty rich. I'm not saying GM's code is junk but it is old and I'm sure they were in a time crunch when they programmed most of these calibrations.
Let me know how the eprom I send you works out. Disclaimer; I can't be held responsible if you use the calibration sent. It's for off-road use only and it is your choice to use it. Since I'm not selling it I can not be held responsible for anything that is done with this code. don't you just love that

 

:hail:
Jon, that is EXACTLY what I needed to hear/read! I was wondering why I was getting a rich condition when I knew well that I had tuned the VE tables. I'll go home and fix this immediately since I am hoping to be driving the TBI Jeep this weekend.
Good stuff! You da MAN!

 

@John: :hail: Ok i think that explains why my car is running like crap
Thank you!!
The Spark tables are displayed correct?


Nebu.

 

Yes, spark tables and everything else seems to be fine.

 

ok its running better now but not perfect.
in open loop its ok, but when the ecm goes in closed loop at 145F its getting richer and richer.

at 145F O2 Volts are 0.8
at 160F its above 1.0 Volt all the time.

what could that be?

 

mine goes richer when fully heat soaked. same with summer use richer on blms.