SD MAF Calibrating- how to prevent Limp Mode?

[grayman]

logging LTFT's for VE table tuning and then MAF calibrating.

(Gary's newbie tuning guide...be careful with his syntax errors and misplaced screen shots...but seems quite comprehensive otherwise)

First day of testing was fine. Turned of PE TPS (set to 100). Copied high Oc to Low Oc fuel timing table. Uplugged Maf. Deleted code 1514. Reset fuel trims.

Made one long logging run. Car was fine at all types of RPMS (full range) but i did not put the car into 100 tps nor more than 3 psi of boost. Also drove around in lower gears and in general broke many laws and beat on the car pretty good. :-)

Got home, saved scan. Went through the LTFT cells. (car basically runs lean at idle and cruising...but I knew that already (AEM). Update the VE table with data from the scanned LTFT's. Get up the next day...load current (updated) PCM file. Go out for scanning run. Wham! car sets off a different MAF failure code and goes into limp mode. PUll over...(forgot the code) clear code and remove it from pcm file. rewrite file to car. start car, start scanner. pull onto the road. WHAM! Not again. Limping into a parking lot...check the code..this time it is different but still maf related P0102. this time i shut off car and delete that code and also p0103 (?) becuase it reads very similar and rewrite the PCM.

Ok, start the car and the scanner again and limp mode keeps being engaged at 4000rpm. period. It does not matter how i reach 4g's...light throttle vs. heavy throttle. As soon as the engine hits 4000 rpm in any gear limp mode sets in. But, no code is shown in the DTC scanner any more. The car just goes into limp mode at 4000 grand. It can be cleared, but no code is shown as before. (refreshing the dtc's and 'waiting' does not work either. But limp mode can be turned off with the DTC scaner 'delete' tool.

I did not make any changes to the pcm file other than updating the VE table with data from the scan the night before. I have also not been reseting the fuel trims for every logging run. I just reset them the very first fime as suggested by Gary.

I have already modified the air delta table (x2) and the fail frequency table, etc. (thanks viper) and all those types of changes are already in the file I am using...albiet that is with the Maf plugged in. (car is fine with maf plugged in...just starting at the starting point by tuning the VE tables and then checking and updating the maf curve.)

Ok, so I have been reading a bunch on this deal. Others seem to get it as well. unfortunatly there is no such thing as a 'completed v6 thread' over at HPTuners forum. Though others may have expereinced this with 99+ cars or something nobody seems to have a solution.

I know there are other ways to tune the fuel ratio. I want to give a shot at calibrating the maf, however. This post is also not concered with 'normal' mode of having the MAF plugged in. The forced induction related maf error codes and tables have already been updated and deleted. Car is fine with maf running. (again, viper tuning guide)

(on prior testing I experemented with scaling up the maf table 'just to see' and it seems to work even to just try diferent multipliers. X1.1 over the entire table richened up the cruise and load AFR's down to averaging high 14's from averaging mid to high 15's. (i am talking cruising...not boost...don't worry, the fmu gets me down to low 11's when i need it.)

oh, yea...stuff like COT lean cruise is turned off, etc.

So, was there ever a conclusion or solution to the limp mode while SD driving in the 99+ (?) cars? Is there a secondary VE table that is hidden from us? (wild shot here)
I can gather good cruising data keeping the car under 4 grand but i would really like data from the rest of the cells.

TIA. g

01 FB A4 3.42
1.9 Rockers/105 Springs
3" Magnaflow LT1 + 3" Carsound Cat
6 psi Powerdyne
For Powerdyne help and guides visit:
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[2002 v6 camaro uncharged]

Re: SD MAF Calibrating- how to prevent Limp Mode?

You have to increase the values in your "Calculated Airflow vs RPM vs Time",table in your EDITOR its under Engine Diagnostic.

[Turbo V6 Camaro]

Re: SD MAF Calibrating- how to prevent Limp Mode?

You have to increase the values in your "Calculated Airflow vs RPM vs Time",table in your EDITOR its under Engine Diagnostic.

what he said the 199 + cars have this table i didn't see it till about 2 months ago

the maf maxs at 260 g/s this table maxs at 178 g/s (table i seen)

way to go GM they get dumb **** prize of the year

any who running with no maf and cut off at 4000 RPM...

umm is your MAP maxing out?

can you please post what codes you deleted with discriptions ?

email me your bin file too me

also are you using the MAF error pid?

there is also a pid for calibrating the injecotor size at every map level

[grayman]

Re: SD MAF Calibrating- how to prevent Limp Mode?

Originally Posted by 2002 v6 camaro uncharged
You have to increase the values in your "Calculated Airflow vs RPM vs Time",table in your EDITOR its under Engine Diagnostic.

what he said the 199 + cars have this table i didn't see it till about 2 months ago

the maf maxs at 260 g/s this table maxs at 178 g/s (table i seen)


Thanks. I just went and multiplied all the cells x2.

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any who running with no maf and cut off at 4000 RPM...

umm is your MAP maxing out?

MAP maxing out at 104 on the first day of SD logging. the next day is when the 1514 code and 0103 codes started happening. With the car going limp the MAP does not quite max out. (gets to about 90+) (MAP also maxes with the maf plugged in for daily driving...when i get on the throttle...about 4000 rpm and up...or quick WOT bursts)

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can you please post what codes you deleted with discriptions ?

P1514 was first code. Deleted it. turned of car and adjuted DTC and reprogrammed car.

P103 then happened. I did same as above. BUT, now the car still goes into limp mode if it gets to 4000rpm OR approximately 60% TPS yet there is no formal code that is listed in the DTC scanner. If you 'clear' the codes from the scanner car returns to normal. Weird that it no longer lists what the code is.

(non of this happens when the maf is plugged in. normal tune is fine.)

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email me your bin file too me

Which one? I have a few. SD bins, daily bins, stock bin, etc. I think i will also send you a config file for the scanner as well as some scans. I need to get a bit more organized first. I feel pretty good about the SD VE table calibration. (other than the fact it does not go over 4000rpm...DOH!) I have not broken down the maf calibration into math. I have the SD tune running the car (cruise) at 14.7. I also calibrated by math the ghetto way...multiplied the entire table by 1.1 (which is real close) and i will be trying 1.12 for the entire table and perhaps 1.14 for the low end of table (idle ...upto 3999hz) and 1.12 for the rest of the table. Either way...that is what will end up happening if i use math and averages...i am just skipping the actual number crunching. it works. with the wideband I knew the car was lean. With the VE tuning in SD mode I also confirmed the car was generaly lean. This has helped me richen up the idle and cruise and part throttle aspect of the tune.

____________________________________

also are you using the MAF error pid?

I gotta go look that up. It seems like I knew what that was once. is it mentioned in your guides?

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there is also a pid for calibrating the injecotor size at every map level

I am pretty sure I don't know about that. I am also pretty sure I don't know what a MAP level is. it seems to read up to 104 kpa? don't know about no levels.


I know I started this thread and then sorta bailed. Things have been happening though... my poor daddyo.... not good. I still get some free time now and then, though. I havent stopped tuning the car or anything. It will just take me a lot longer than I planned.

(i also can't start the injector coversion yet nor even the fuel pump upgrade. that would put too much down time on the supercharged ambulance. I do plan on keeping up with learning this program.)

Thanks for all the help. g

[grayman]

Re: SD MAF Calibrating- how to prevent Limp Mode?

oh yea,
I have not had a chance to put the car back into speed density to test 'uncharged's' tip about altering that tps vs airflow vs rpm table. As i stated above i just multiplied the entire table by 2 but have not loaded that file into the pcm yet. I will try it when I can.


Not sure what all I can do with a car that uses an FMU. I can manipulate things like part throttle, PE, etc. but at WOT the injectors hit 125% and sometimes even 147%. I am glad they work at all. (and the recent deal with the fuel pressure no longer rising to 85psi...cant really drive the car real hard right now.) I plan on rechecking the NR tables. I can do that coming home from work, etc. It might be a little different now that i have the maf calibrated and generaly richened up the idle-cruise-low boost modes of engine.

[Turbo V6 Camaro]

Re: SD MAF Calibrating- how to prevent Limp Mode?

you do know that tune the VE your only tuning if the maf accualy fails right? that the only time the VE talbe is used :poke:

i would tune the injecotrs talbe and the MAF talbe those are the 2 that matter a lot

[grayman]

Re: SD MAF Calibrating- how to prevent Limp Mode?

you do know that tune the VE your only tuning if the maf accualy fails right? that the only time the VE talbe is used :poke:

i would tune the injecotrs talbe and the MAF talbe those are the 2 that matter a lot

by SD tuning the VE table you can use the new VE table to compare (percentage) how far off the maf is from being calibrated. Then you calibrate the maf with the new VE table. That seems like square one to me. The car is lean (was) because so much air was passing vs the stock intake system. The maf is now calibrated and I can move on to the next stages.

When I get more time i will ask you again about this injector PID you mentioned. I tried your suggestion of setting the injector table to all the same rather than the stock way. our stock 22# injectors have a strange table. other injectors tables scale from low to high but the 22# table moves up and down and finaly terminates with the highest #. odd.
anyway, the car ran real crappy. i may have forgotten to reset the fuel trims, though. i have since set that table back to stock and calibrated the maf with the new ve table.

i figure when i start getting time again i will move on to fuel tuning (part throttle or as much as I can do) and then move on to spark table. It is gonna be a long while now before I can upgrade the injectors. things are going on that are more important. anyway, I will keep you posted. now I am off to california couple of days.

[Turbo V6 Camaro]

Re: SD MAF Calibrating- how to prevent Limp Mode?

by SD tuning the VE table you can use the new VE table to compare (percentage) how far off the maf is from being calibrated. Then you calibrate the maf with the new VE table. That seems like square one to me. The car is lean (was) because so much air was passing vs the stock intake system. The maf is now calibrated and I can move on to the next stages.

When I get more time i will ask you again about this injector PID you mentioned. I tried your suggestion of setting the injector table to all the same rather than the stock way. our stock 22# injectors have a strange table. other injectors tables scale from low to high but the 22# table moves up and down and finaly terminates with the highest #. odd.
anyway, the car ran real crappy. i may have forgotten to reset the fuel trims, though. i have since set that table back to stock and calibrated the maf with the new ve table.

i figure when i start getting time again i will move on to fuel tuning (part throttle or as much as I can do) and then move on to spark table. It is gonna be a long while now before I can upgrade the injectors. things are going on that are more important. anyway, I will keep you posted. now I am off to california couple of days.

some newer cars don't like all the same vaules for the injectors its a hit and run thing....

take you fuel psi at idle and use the thing in HP Tuners to find the real flow rate do that for every area the 100 map will be your max fuel psi under boost

exaple my injectors are 65# @43.5 psi but my car is always at 47 psi = 67# flow

at 100 map my fuel 53+ using this makes my new value 71lb/hour

FYI you have a WBO2 you don't need to calibrate the VE talbe the WBO2 maf error % is all you need

[slow6]

Re: SD MAF Calibrating- how to prevent Limp Mode?

I set mine to 21.99 all across the board like viper told me to.
Now it doesnt go into limp mode and throw codes.
but testing my REAL fuel psi sounds like a great idea, cant wait to go to
harbor freight!

[grayman]

Re: SD MAF Calibrating- how to prevent Limp Mode?

Thanks Viper,
I still don't have the mpvi interface. It is gonna be a while before i can get the wb data logged into hpt scans.

Thanks for reminding me about the fuel psi injector calibration. I guess they could be off a tad. my normal and sustained fp is always 51. most cars seem to be 47 on average.

[slow6]

Re: SD MAF Calibrating- how to prevent Limp Mode?

some newer cars don't like all the same vaules for the injectors its a hit and run thing....

take you fuel psi at idle and use the thing in HP Tuners to find the real flow rate do that for every area the 100 map will be your max fuel psi under boost

exaple my injectors are 65# @43.5 psi but my car is always at 47 psi = 67# flow

at 100 map my fuel 53+ using this makes my new value 71lb/hour

FYI you have a WBO2 you don't need to calibrate the VE talbe the WBO2 maf error % is all you need

that would really change up my "Injector Flow Rate vs. KPA VAC" table. because the actual real fuel pressure differs at different manifold pressures(0-100 MAP kPA).
The computer goes through alot of calculations for the final outcome of the actual real AFR.
I'm saying you cant just leave your "Injector Flow Rate vs KPA VAC" table just straight "21.99" across the board huh

[Turbo V6 Camaro]

Re: SD MAF Calibrating- how to prevent Limp Mode?

that would really change up my "Injector Flow Rate vs. KPA VAC" table. because the actual real fuel pressure differs at different manifold pressures(0-100 MAP kPA).
The computer goes through alot of calculations for the final outcome of the actual real AFR.
I'm saying you cant just leave your "Injector Flow Rate vs KPA VAC" table just straight "21.99" across the board huh

leveing it one number across the board works and made dialing in the AFR easy for me.... but then it looks like injectors are maxed and it's adding more fuel, then it thinks. SO i then bagint ot have troubles with the AFR looking like a sound wave.

i'm hoping this new methode stops that

i have been playing with these for about a week now and my WB stay REALLY close to 14.7:1 even with my exhaust leak

i havn't had a chance to see how it affects WOT yet, and if it makes getting the AFR as hard as i thought it was before.....

when i figure it out i will update the write up... the stock FPR is 1:1 as a FYI

but this only works for people that can acually look at their FP and correct it.....

there's a few things i need to update about it but i just hvn't had the time, if i dont work this weekend hopfully i can add 3-4 wirte ups and make some corrections to the page

[slow6]

Re: SD MAF Calibrating- how to prevent Limp Mode?

the new writeups would be awesome for us learning challenged people.