Help! SCT tuner mistake

[SicilianMobster]

Please, bear with me I new with this tuning stuff. me being a dumb@$$ i decided to screw around with the tuner about three weeks after i bought the car. AFR's were right around 10.9-11.2 at WOT. Now they are running at like 12.4-13.3 w/ the 3.5 pulley..... It has a pre-loaded tune on it for a 3.25 pulley (check mod list below). Im wondering how bad i could have screwed it up because it does feel a little different..... I tried to get the datalogging set up but its not letting me do it for some reason. I dont have a tuner anywhere near here thats any good. So i guess my question is will it be ok running the "3.25" pulley tune if i just adjust the WOT Air/Fuel to 14% richer or do i need to trailer it 600 miles back to salt lake city and have the people who built the motor tune it????

Dont know if it has anything to do with the tune but at start up the intake sounds like its sucking in MASSIVE amounts of air. Idle's fine.

Any help or advice is appreciated :beer:

 

[01yellercobra]

If you have a tune for a 3.25" pulley, but you're running a 3.5" pulley you should have to lean it out, not richen it up. What did you adjust on the tuner? You should be able to reload the tune without changing any of the paremeters. Make sure you're air filter is still connected. That could cause the sucking sound you're hearing.

 

[Stanger00]

Advanced Engine Development in Cameron Park (Shingle Springs) CA can help you out if you cant fix the parameters yourself. They are a lot closer than 600 miles thats for sure. They are about 50 miles west from South Lake Tahoe.

Advanced Engine Development - Engine Builds, Dyno Tuning, Installs, Suspension

Shaun does the tuning. Give them a call if you cant dial in your A/F...You should lean your tune out for the larger pulley not richen.

 

[harvboi05]

what does the pulley have to do with his fuel calibration? as long as the map he is running at the flow value the 3.5" pulley provides is calibrated for the proper WOT afr, he shouldnt need to adjust anything.

a 3.5" and 3.25" pulley can be run on the same calibration, theyre just at two different points for load and flow values. as long as the entire maf xfer function has been adjusted hes good to go.

 

[Stanger00]

The way I read it is the OP only has the hand held device to make minor adjustments. Unless I read wrong.

 

[stangliter04]

as long as the entire maf xfer function has been adjusted hes good to go.

This ^^^

 

[SicilianMobster]

The way I read it is the OP only has the hand held device to make minor adjustments. Unless I read wrong.

Yea.... I can adjust timing throughout rpm range, WOT A/F, Rear End Gear, Idle Rpm, Driving RPM, rev limiters, tire rotation per mile (<--- i think thats what it is. something to do with the rotation of the tires.

but when i load the 3.25 tune every value i can adjust w/ the hand held is set at the base value? or is it possible that the tuner locked the major parts of the tune and only allowed for those minor adjustments?

 

[mastwolf]

Yea.... I can adjust timing throughout rpm range, WOT A/F, Rear End Gear, Idle Rpm, Driving RPM, rev limiters, tire rotation per mile (<--- i think thats what it is. something to do with the rotation of the tires.

but when i load the 3.25 tune every value i can adjust w/ the hand held is set at the base value? or is it possible that the tuner locked the major parts of the tune and only allowed for those minor adjustments?

Its a good possibility that the tuner has not giving you much adjustment in the hand held.

What are the mods done to the car?

Chris

 

[SicilianMobster]

ttttt

 

[encasedmetal]

pm me if you like OP and tell me exactly what you did in your handheld. being that you have very limited abilities with your handheld this should be a very easy fix. and do not run your car at that AFR at WOT. per your base fuel tables your should be around 11.5-11.8 (or 0.782-0.803) with a built motor on a safe tune. more like 11.0 on an unbuilt tune, meaning your base fuel value should be around 0.748

 

[encasedmetal]

This ^^^

not neccessarily. a different blower ratio means that the air values in the xfer function would be different. regardless though as the OP does not have access to the xfer tables via handheld.

 

[SicilianMobster]

I would love to be able to get my datalog working so i could see exactly whats going on..... I would have no idea what i was looking at but it sounds like you would lololol

 

[SicilianMobster]

probably has something to do with the high a/f's but it throws lean bank 1 and 2 codes every 24-26 miles

 

[SicilianMobster]

checked for vaccum leaks and found nothing

 

[encasedmetal]

you either have a mechanical issue throwing you lean (and yes your bank 1 and bank 2 are due to your lean conditions afr wise) or you changed something in your handheld. I cannot guide you without a datalog or knowing what you changed since I cant acces your tune due to not being a dealer

 

[BruceH]

Just adding to what has already been said about the tune and maf xfer.

IMO your tune has an incorrect maf xfer. The tuner used the fuel tables to tune around the problem instead of getting the maf xfer correct.

Try putting the previous pulley back on and datalogging stft and ltft for both banks. They shouldn't vary more than 6% (.06 reading) during most closed loop driving.

 

[encasedmetal]

Just adding to what has already been said about the tune and maf xfer.

IMO your tune has an incorrect maf xfer. The tuner used the fuel tables to tune around the problem instead of getting the maf xfer correct.

Try putting the previous pulley back on and datalogging stft and ltft for both banks. They shouldn't vary more than 6% (.06 reading) during most closed loop driving.

6% my ass- more like 1%

 

[BruceH]

6% my ass- more like 1%

No, 6% is the accepted deviation. Changes in atmospheric conditions will require the fuel trims to change in order to maintain the stoichometric ratio called for in the tune.

 

[encasedmetal]

No, 6% is the accepted deviation. Changes in atmospheric conditions will require the fuel trims to change in order to maintain the stoichometric ratio called for in the tune.

that's what adaptive learning is for. and that's why your STFT need to be so close, so that when you encounter changes in relation to sealevel and seasonal temp. changes your car knows where to go. 6% is alot, meaning you would be running 13.81- 15.57afr in relation to stoich per your 6% variance in correct fueling.

 

[BruceH]

that's what adaptive learning is for. and that's why your STFT need to be so close, so that when you encounter changes in relation to sealevel and seasonal temp. changes your car knows where to go. 6% is alot, meaning you would be running 13.81- 15.57afr in relation to stoich per your 6% variance in correct fueling.

I was referring to the fuel trims (adaptive learning) in my original post. That's why I said stft and ltft. Fuel trims are the correction being made to keep stoich, you have it backwards. What did you read?

There is no way your stft and ltft are only varying 1%.

The OP has all the signs of an improperly scaled maf xfer function. More than likely his tuner used the value file and left it. When the car was on the dyno the fuel tables were adjusted to get commanded lambda instead of fixing the maf xfer.