Advance and LTFT run high. what to do?

[moosebjm]

Im new to tuning and need help figuring out what to do to fix two issues. my advance at idle is 20 is this high and if so how can I correct it? the other is I am running lean my ltft at idle is about 21. I know I need to update my MAF chart but how should I go about doing this? My mods are 01GTP intercooled with 3.3 pulley, ported lower intake manifold, ported SC, 42.5 injectors, 1.9 rolling rockers, and headers and 3inch exhaust. thanks for the help.

[coachcrow56]

Use your scanner to read your LTFT's for at least a 20 to 30 minute drive. Copy and paste the numbers into your VCM Editor Maf Calibration section---use Paste Special and multiply % minus half. Reset your Fuel Trims----drive for 20 to 30 minutes again using your Scanner---and repeat the process. Try to get your LTFT's to + or - 5.
20 degrees timing at idle is OK. Make sure you do not have any KR

[TurboGP33]

Be sure your Fuel Injector vs Voltage tables are correct. Sometimes running lean at idle can be caused by the ign voltage dropping and the injectors are commanded to little.

Before you tune the MAF, make sure the LTFT aren't following a voltage drop at idle.

If so, massage that table accordingly. Multiplying that table won't work as I believe it is ms added/subtracted kind of table.

[moosebjm]

thanks for all the help but Ive messed around with my flow rate vs kpa and I believe I have that set correctly for the 42.5 injectors. but Im still rock solid lean (16.4%) LTFT at idle. ive even messed around with the off set vs volts and offset vs pw vs MAP and I have yet to get the LTFT idle to move from 16.4. once I get the RPM up above 1000 the LTFT goes to the +/-5 but I can not get the idle to move. any suggestions? Oh and once any boost is added it goes extremely rich (22.5%) LTFT.

[TurboGP33]

Log your Barometric Pressure and see if your PCM is registering proper atmosphere. Then go into boost and see if the PCM is adjusting the barometric pressure value with max MAP readings.

If you are using a NA MAP, that is what will happen. When I hit first boost the Baro goes up to 105kPa (maximum of MAP sensor). It is called Barometric Relearn Function and can mess with your tune big time if you don't correct it.

A quick fix is simply tune with data after 1st boost. Then, the car will run off a little lean when started up but will be spot on in tune after the first boost.

Or install a 2 bar map. The Baro relearn function only kicks in if the MAP hits a plateau and doesn't rise further with boost. With a 1 bar, it hits 105 kPa and stays there. Which triggers the relearn function, thinking the car is in NA WOT and the atmosphere pressure is 105kPa. Useful if you drive from a mountain town to the shore often.

[thebeewantsboost]

http://www.hptuners.com/forum/showth...oop-Maf-Tuning
good writing for tuning your maf. the PE can't be tuned by using fuel trims. Check what TurboGP mentioned and see if the fuel trims at idle are off after you hit boost. unless you have a 2 bar map.