AFR Incredibly high?

[SpeedFromSwede]

Here is the data map for my OFT stage 1 tune. I'm currently running a perrin 3" BIGMAF Intake and I have used their set MAF scaling. I'm not sure how useful this info on this data map are but it seems like my AFR and LTFT are off with my LTFT running almost at -14 and AFR in the low 20's.

From what I've read AFR should be around 14.7 and LTFT values should be no more than 10. I'm sort of a noob when it comes to this, but with this low of LTFT readings I'm running rich? If someone can clarify if these are normal readings for this tune or if I need to correct something that would be helpful.

Lastly, It has been over 100 miles of normal driving and I'm still getting the dead spot in the pedal. I'm assuming I screwed something up somewhere, I just don't know where.

http://datazap.me/u/speedfromswede/b...=0&data=1-8-10

[phrosty]

AFR of 20 happens when you lift off the throttle. This is normal.

LTFT at -13 is definitely not normal though. You'll want to correct this.

[SpeedFromSwede]

Originally Posted by phrosty

AFR of 20 happens when you lift off the throttle. This is normal.

LTFT at -13 is definitely not normal though. You'll want to correct this.

Thanks for the feedback. What would be the best way to correct fuel trims? The only thing I can think of is a vacuum leak or rescaling the MAF.

[phrosty]

I'd double check your MAF scale is the correct one from Perrin -- I'd expect you to be within 5% when using the one they provide.

Other than that -- yea, check for a leak or a dirty MAF sensor. If it's a new install, oil might have slung off the filter if you didn't give it a wipe down before putting it on.

[steve99]

+1 on what @phrosty said


maf scaling here ans 3" perrin scale at bottom of post


http://www.ft86club.com/forums/showthread.php?t=64790




.

[SpeedFromSwede]

Double checked the MAF scaling and it is the correct one from Perrin. Looks like I'll have to check for leaks and my MAF sensor. Other than that, would you recommend I use vgi custom maf scaling? http://www.romraider.com/forum/viewt...p?f=32&t=10481

[steve99]

Originally Posted by SpeedFromSwede

Double checked the MAF scaling and it is the correct one from Perrin. Looks like I'll have to check for leaks and my MAF sensor. Other than that, would you recommend I use vgi custom maf scaling? http://www.romraider.com/forum/viewt...p?f=32&t=10481

Yes its a great utility.

sometimes takes a couple of attempt to get scaling corrected when its that far off.

[SpeedFromSwede]

Originally Posted by phrosty

I'd double check your MAF scale is the correct one from Perrin -- I'd expect you to be within 5% when using the one they provide.

Other than that -- yea, check for a leak or a dirty MAF sensor. If it's a new install, oil might have slung off the filter if you didn't give it a wipe down before putting it on.

Alright, so I checked the MAF sensor and it was clean, I also checked inside the intake tube itself and it was also clean. Went ahead and wiped down the MAF sensor just in case.

The next thing was for vacuum leaks, unless there is one further up the intake towards the filter, I couldn't find any. I took off the inlet tube to the throttle body and re-clamped it. Likewise for the inlet tube to the intake itself. Wasn't any different in the LTFT readings, around -7 at idle and -12 at 2000 rpm until release of throttle it decreases again. The thing that is peculiar is the STFT at idle being around 1.5 and at constant throttle being 0.

[White64Goat]

You're like 15 minutes from Mach V Motorsports in Sterling. Dan can probably help you if you don't get it yourself.

[steve99]

Originally Posted by SpeedFromSwede

Alright, so I checked the MAF sensor and it was clean, I also checked inside the intake tube itself and it was also clean. Went ahead and wiped down the MAF sensor just in case.

The next thing was for vacuum leaks, unless there is one further up the intake towards the filter, I couldn't find any. I took off the inlet tube to the throttle body and re-clamped it. Likewise for the inlet tube to the intake itself. Wasn't any different in the LTFT readings, around -7 at idle and -12 at 2000 rpm until release of throttle it decreases again. The thing that is peculiar is the STFT at idle being around 1.5 and at constant throttle being 0.

OK then it looks like its just the maf scaling needs adjusting.

log about 30 minutes of smooth driving at varying rpm and loads, and not too much idling.

feed that into vgi program and do the closed loop scaling.

once you have that sorted do the open loop wot scaling by logging 3 or 4 wot runs from 2000-7000

[mad_sb]

Originally Posted by SpeedFromSwede

Here is the data map for my OFT stage 1 tune. I'm currently running a perrin 3" BIGMAF Intake and I have used their set MAF scaling. I'm not sure how useful this info on this data map are but it seems like my AFR and LTFT are off with my LTFT running almost at -14 and AFR in the low 20's.

From what I've read AFR should be around 14.7 and LTFT values should be no more than 10. I'm sort of a noob when it comes to this, but with this low of LTFT readings I'm running rich? If someone can clarify if these are normal readings for this tune or if I need to correct something that would be helpful.

Lastly, It has been over 100 miles of normal driving and I'm still getting the dead spot in the pedal. I'm assuming I screwed something up somewhere, I just don't know where.

http://datazap.me/u/speedfromswede/b...=0&data=1-8-10

Be sure to account for the short term trim as well, Most spots your combined short and long term trim error is less than 10% there is probably a small region where the maf scale is off that needs to be adjusted, leading to long term trim build up and short term trim correction when outside of the area that needs to be re scaled.

You also need to log throttle position.

[Turdinator]

What tune are you running OP?

[SpeedFromSwede]

Originally Posted by Turdinator

What tune are you running OP?

Stage 1 OFT with edited maf tables for the 3" intake.

[steve99]

Originally Posted by SpeedFromSwede

Stage 1 OFT with edited maf tables for the 3" intake.

V1.5x OFT stage 1 tune or V2.062 Stage 1 OFT tune. The V1.5 had offset maf scaling.

If you not already use the V2.062 stage 1 rom if your going to edit maf scaling.