tuning question

[Josh Hapka]

is there like a certain time like after you flash that it takes your car to start using that tune or is it instant.. and why is it that i make an adjustment in the maf for my maf tune.. and it is like it doesnt have any affect on the LTFT table at all.. also when you tune do you have to turn your PE tables to 0 when you tune?

and one more questions. when you do a maf tune do you have to do it like 4000-4999 5000-5000 and so on ?

[robfromlouisville]

i reset my trims after a pcm flash,this is how i tune my maf ,,,idle range 1000-3999,cruise range 4000-8999,, on and on . if you do a tune and its the same as before maybe your 02sensor is going out,when my o2 was going out ltfts would stay the same i got an 02 code then i unpluged it an the car ran alot better....lol..

[Josh Hapka]

thank you....so i can tune my maf with just my wide band o2 sensor right.

[jackedupcanyon]

is there like a certain time like after you flash that it takes your car to start using that tune or is it instant.. and why is it that i make an adjustment in the maf for my maf tune.. and it is like it doesnt have any affect on the LTFT table at all.. also when you tune do you have to turn your PE tables to 0 when you tune?

and one more questions. when you do a maf tune do you have to do it like 4000-4999 5000-5000 and so on ?

Instant but learned values have to be learned and adjusted accordingly (that is why you reset your fuel trims). LTFT = LONG TERM fuel trims.....takes a LONG time to learn and adjust. Do not have to set PE tables to 0 but you should not be trying to tune PE without a wideband. Have a wideband? Makes tuning easier, faster and more accurate.

[Perforator]

thank you....so i can tune my maf with just my wide band o2 sensor right.

I would use the wideband for WOT tuning only. Use the O2 sensor for closed loop.

[Josh Hapka]

and after you reset your fuel trims... roughfly how long does it take for your LTFT to start reading corectly, cause i noticed when i reset the fuel trims it was only runing -2,,0,,,,-1 wich i know is incorect... im asking cause after i reset them i went for a 45 mile drive and it was around those values. the whole way..

[jackedupcanyon]

Everything I have read says 50 minutes or 100 miles.

[Josh Hapka]

o wow... ok.. thanks a bunch...now can you tune with just your wide band o2 or do you have to do your LTFT first than tune by your wide band 02?

[jackedupcanyon]

Can tune with just the WB. Just calibrate and tune away. No time or mileage delays.

[Josh Hapka]

ok heres another one.... under the PE fuel adder vs rpm vs time...... what is the optimal range for it to run at.... i have a 2002 3.8 v6 camaro..... wich is naturally aspirated...(no turbo or supercharger) right now its running around 900 to 950 i believe..

[robfromlouisville]

i have my power enrich vs fuel adder vs rpm vs time table set to all 0's

[n0dih]

Watch the fuel trims, it will reset those cells in a couple seconds once it hits them, unless they are WAAAY off, still takes a very small amount of time to relearn, you just have to hit all the cells that are filled with other values (which depending on how you drive could take a long while, if ever...). I assume the values are reset to 128 (0%) when you reflash.

Everything I have read says 50 minutes or 100 miles.

[jackedupcanyon]

Yes. Depends on how many times you hit that cell. The more you hit it the faster it learns. Can always change your histos to required more hits before it shows the data to filter out more inaccurate information.

Do not think the fuel trims reset when you flash. I typically go into the VCM Controls in the scanner and manually reset the trims if I have adjusted the VE tables.