Ok so here is my situation, I was at the track on wednesday just doing some data logging and had some issues with my afr. My maf sensor was hitting 4.9v at about 5800rpm, when that happened my afrs went way lean. I upgraded my maf housing to 3in. I did some injector scaling, and am pretty happy with it for now. The max voltage I am seeing now at the same boost levels is 4.7v. I went back to the track and did some more logging. The problem is that my afr goes crazy lean, and egt's reflect that the mixture is actually lean, 920c. I know these #'s are crazy, but with the fuel that I run, I have more room for safety. Anyone have any ideas as to what is happening. Fuel pump failing? Injectors? I bore scoped the cylinders and there is no damage, compression is 144-148 in all holes.



DATA1

, , , ,Load,Knock, , , Mod, Mod, , Mod, WB
RPM, MAP, MAF,TPS,Site,Count, Ign#1, Inj#1, Ign, Fuel,Boost, MAF, AFR
, psia, V , % , , , deg , duty , deg, % ,(CL) , V ,
696,-11.2,1.1, 1, 00, 00, +17.6, 1.2,ECU. , +0.1,500.00,1.1, 12.71
719,-11.2,1.1, 0, 00, 00, +17.7, 1.2,ECU. , +0.1,500.00,1.1, 12.74
705,-11.2,1.1, 1, 00, 00, +17.9, 1.2,ECU. , +0.1,500.00,1.1, 12.75
714,-11.2,1.1, 1, 00, 00, +17.8, 1.7,ECU. , +0.1,500.00,1.1, 12.78
691,-11.2,1.1, 0, 00, 00, +17.7, 1.2,ECU. , +0.1,500.00,1.1, 12.75
656,-11.8,1.2, 2, 00, 00, +23.6, 1.4,ECU. , +0.1,500.00,1.1, 14.15
684,-11.6,1.2, 2, 00, 00, +23.1, 1.4,ECU. , +0.1,500.00,1.1, 14.58
742,-11.0,1.2, 0, 00, 00, +19.8, 1.5,ECU. , +0.1,500.00,1.1, 15.18
814,-10.8,1.2, 1, 00, 00, +15.3, 1.9,ECU. , +0.1,500.00,1.1, 15.37
795,-10.6,1.5, 18, 00, 00, +17.7, 14.2,ECU. , +0.1,500.00,2.0, 14.37
1551, -8.3,2.1, 34, 10, 00, +30.1, 12.0,+35.0, +0.1,500.00,2.0, 13.06
2888, -6.3,2.4, 25, 00, 00, +32.1, 10.9,ECU. , +0.1,500.00,2.3, 12.93
3835, -4.5,2.6, 24, 00, 00, +37.4, 12.8,ECU. , +0.1,500.00,2.4, 13.81
4553, -4.0,2.5, 20, 00, 00, +45.1, 12.7,ECU. , +0.1,500.00,2.3, 14.33
4938, -6.1,2.4, 20, 00, 00, +42.8, 10.7,ECU. , +0.1,500.00,2.2, 13.95
5159, -7.9,2.4, 21, 00, 00, +42.2, 11.9,ECU. , +0.1,500.00,2.2, 13.81
5249, -8.7,3.0, 39, 10, 00, +45.0, 26.4,+20.5, +0.3,LCM. ,2.9, 13.92
5473, -6.7,3.4, 83, 10, 00, +41.4, 33.1,+20.5, -1.5,LCM. ,3.1, 17.25
5473, -4.3,3.6, 99, 10, 00, +39.3, 35.7,+20.5, -1.5,LCM. ,3.2, >25:1
5518, -1.4,3.7,100, 10, 00, +39.0, 40.1,+20.5, -1.5,LCM. ,3.3, >25:1
5509, +1.1,3.7,101, 20, 00, +39.0, 41.0,+20.5, -1.5,LCM. ,3.3, >25:1
5359, +2.1,3.8,102, 20, 00, +39.4, 44.5,+20.5, -1.3,LCM. ,3.5, >25:1
5509, +3.5,3.7,100, 30, 00, +39.5, 46.7,+20.5, -0.2,LCM. ,3.5, >25:1
5274, +1.9,2.3, 0, 00, 00, +16.2, 17.1,ECU. , +0.1,LCM. ,2.9, >25:1
4803, -2.2,3.2, 2, 00, 00, +42.9, 13.3,ECU. , +0.1,500.00,2.9, >25:1
5167, -4.3,3.5, 52, 10, 00, +36.3, 40.1,+20.5, -0.4,500.00,3.2, 22.62
5282, -8.1,2.5, 3, 00, 00, +41.6, 10.3,ECU. , +0.1,LCM. ,2.8, 13.09
5482, -6.9,3.7,100, 10, 00, +39.1, 36.1,+20.5, -1.3,LCM. ,3.2, 12.18
5027, -2.8,3.7,100, 10, 00, +36.3, 47.6,+23.7, +0.3,500.00,3.5, 15.08
4997, +0.0,4.0,102, 30, 00, +23.9, 56.9,+23.7, +1.0,500.00,3.8, 13.06
4688, +5.7,4.2,102, 50, 00, +18.9, 61.3,+21.8, +1.9,500.00,3.8, 10.01
4655, +9.8,4.1,102, 80, 00, +19.1, 61.5,+22.0, +0.4,500.00,3.8, 9.67
5073,+14.3,4.5,102, 90, 00, +18.5, 74.0,+20.6, -1.8,500.00,4.1, 10.15
5817,+17.8,4.6,102,100, 00, +23.6, 78.2,+20.5, -2.4,500.00,4.1, 10.56
6195,+19.6,4.6,102,100, 00, +22.7, 79.7,+20.5, -2.4,500.00,4.2, 10.87
6337,+20.0,4.6,102,100, 00, +23.9, 78.1,+20.5, -2.4,500.00,4.1, 11.24
7077,+19.4,4.7,102, 90, 00, +29.3, 80.3,+20.5, -1.8,500.00,4.3, 11.30
6706,+17.0,4.6,102, 70, 00, +34.9, 66.0,+20.5, -0.9,LCM. ,3.9, 11.42
4761,+15.3,4.0,104, 70, 00, +32.3, 56.1,+20.8, +1.5,500.00,3.8, 16.44
5216,+14.9,4.4,105, 80, 00, +19.6, 70.8,+20.7, -2.6,500.00,4.0, 22.91
5717,+15.9,4.6,105,100, 00, +17.4, 75.9,+20.5, -2.2,500.00,4.1, 12.53
6105,+18.6,4.6,106,100, 00, +19.2, 78.4,+20.5, -2.4,500.00,4.1, 11.12
6472,+20.2,4.7,105,100, 00, +21.9, 80.7,+20.5, -2.3,500.00,4.2, 11.37
6887,+20.8,4.7,104,100, 00, +26.0, 80.3,+20.5, -1.6,500.00,4.2, 11.43
6830,+20.6,4.7,104,100, 00, +33.6, 53.4,+20.5, -2.2,LCM. ,3.9, 11.65
4681,+19.6,4.1,104,100, 00, +29.3, 54.5,+20.2, -1.0,500.00,3.7, 17.25
5333,+18.4,4.6,106, 90, 00, +23.3, 75.6,+20.5, -2.0,500.00,4.1, >25:1
5583,+19.2,4.6,106,100, 00, +22.3, 77.0,+20.5, -2.2,500.00,4.1, 15.50
5931,+19.0,4.7,106,100, 00, +19.2, 79.7,+20.5, -2.4,500.00,4.2, 14.15
6161,+19.8,4.7,106,100, 00, +21.1, 79.8,+20.5, -2.4,500.00,4.2, 14.70
6385,+20.4,4.7,106,100, 00, +22.8, 82.7,+20.5, -2.4,500.00,4.2, 14.87
6472,+19.8,4.7,106,100, 00, +24.3, 84.8,+20.5, -2.3,500.00,4.2, 14.92
6761,+20.0,4.7,105,100, 00, +26.5, 81.7,+20.5, -2.1,500.00,4.3, 15.02
6901,+20.0,4.7,105,100, 00, +28.1, 80.7,+20.5, -2.1,500.00,4.2, 15.02
6706,+19.8,4.7,105,100, 00, +33.2, 67.2,+20.5, -2.2,LCM. ,3.9, 15.80
5333,+19.2,4.2,104, 90, 00, +25.0, 67.4,+20.5, -2.2,500.00,4.0, >25:1
5509,+18.6,4.6,105, 90, 00, +21.8, 77.8,+20.5, -2.1,500.00,4.2, >25:1
5611,+19.6,4.6,105,100, 00, +21.9, 79.4,+20.5, -2.1,500.00,4.2, 14.74
5717,+20.6,4.7,106,100, 00, +22.1, 80.3,+20.5, -2.4,500.00,4.2, 14.49
5941,+22.1,4.7,106,100, 00, +19.2, 83.3,+20.5, -2.4,500.00,4.2, 14.83
6016,+22.9,4.7,106,100, 00, +19.2, 80.1,+20.5, -2.4,500.00,4.2, 14.96
6172,+23.1,4.6,106,100, 00, +20.4, 83.0,+20.5, -2.4,500.00,4.2, 14.96
6172,+22.7,4.7,106,100, 03, +20.9, 84.1,+16.5, -2.4,500.00,4.2, 15.02
6349,+22.1,4.7,105,100, 00, +22.1, 83.9,+16.5, -2.4,500.00,4.2, 15.08
6422,+21.7,4.7,105,100, 00, +23.1, 85.9,+16.5, -2.4,500.00,4.2, 15.12
6510,+20.8,4.7,105,100, 00, +23.6, 85.8,+20.5, -2.3,500.00,4.2, 15.12
6485,+21.0,4.7, 66,100, 00, +25.4, 72.1,+20.5, -2.4,LCM. ,3.9, 15.18
5817,+15.7,2.7, 0, 00, 00, +40.7, 45.1,ECU. , +0.1,LCM. ,3.5, >25:1
5241, +7.4,3.5, 0, 00, 00, +39.3, 33.7,ECU. , +0.1,LCM. ,3.1, >25:1
4566, +1.3,3.8, 72, 10, 00, +33.8, 40.6,+24.0, +0.8,500.00,3.3, >25:1
4748, -2.2,3.8,100, 10, 00, +32.0, 53.0,+24.0, +0.4,500.00,3.7, 13.81
4823, +1.3,4.2,100, 60, 00, +21.2, 72.9,+21.4, +1.8,500.00,4.0, 10.11
4591, +9.0,4.2, 0, 00, 00, +21.3, 18.2,ECU. , +0.1,500.00,3.7, 9.59
4649, +7.8,3.7, 0, 00, 00, +31.7, 42.2,ECU. , +0.1,500.00,3.3, 10.95
4816, +3.3,3.4, 1, 00, 00, +39.1, 42.2,ECU. , +0.1,500.00,3.1, 12.49
4668, -3.2,3.1, 0, 00, 00, +23.3, 42.2,ECU. , +0.1,500.00,2.8, 11.61
4623,-10.8,2.9, 1, 00, 00, +23.5, 42.2,ECU. , +0.1,500.00,2.7, 11.48
4585,-11.6,2.8, 0, 00, 00, +23.3, 42.2,ECU. , +0.1,500.00,2.5, 12.39
4504,-12.2,2.7, 0, 00, 00, +23.3, 42.2,ECU. , +0.1,500.00,2.4, 15.72
4486,-12.4,2.5, 0, 00, 00, +23.4, 42.2,ECU. , +0.1,500.00,2.3, >25:1
4380,-12.6,2.5, 0, 00, 00, +23.3, 42.2,ECU. , +0.1,500.00,2.3, >25:1
4380,-12.6,2.4, 0, 00, 00, +23.3, 42.2,ECU. , +0.1,500.00,2.2, >25:1
4329,-12.6,2.3, 0, 00, 00, +23.4, 42.2,ECU. , +0.1,500.00,2.2, >25:1
4334,-12.6,2.2, 0, 00, 00, +23.4, 42.2,ECU. , +0.1,500.00,2.1, >25:1
4323,-12.6,2.2, 0, 00, 00, +23.3, 42.2,ECU. , +0.1,500.00,2.1, >25:1
4262,-12.6,2.2, 0, 00, 00, +23.5, 42.2,ECU. , +0.1,500.00,2.0, >25:1
4257,-12.6,2.1, 0, 00, 00, +23.4, 42.2,ECU. , +0.1,500.00,2.0, >25:1
4230,-12.6,2.1, 0, 00, 00, +23.4, 42.2,ECU. , +0.1,500.00,2.0, >25:1
4208,-12.6,2.1, 0, 00, 00, +23.5, 42.2,ECU. , +0.1,500.00,2.0, >25:1
4187,-12.6,2.1, 0, 00, 00, +23.5, 42.2,ECU. , +0.1,500.00,1.9, >25:1

Sounds like you did the right thing by upgrading your MAF housing. With the colder weather, the MAF sensor was going beyond it's usable resolution. More info in this thread:

http://forums.nasioc.com/forums/showthread.php?t=645472

Steve.

Make sure you have the FCD switch flipped away from the main UTEC connector. If you don't the stock ECU will try to cut the duty cycle on the fuel pump when you run above 20psi of boost.

-Nathan
www.turboxs.com

The FCD switch is in the correct position. I went out and reset everything, maybe that will do something, I don't know. I will make some more logs saturday and see what happends.

Any chance your o2 sensor-to-TUNA needs to be recalibrated?

I would've thought that with the latest firmware's ability to scale the injectors, that you wouldn't need a larger MAF tube.

Any chance your o2 sensor-to-TUNA needs to be recalibrated?

I would've thought that with the latest firmware's ability to scale the injectors, that you wouldn't need a larger MAF tube.

You'll always need a larger MAF if you're flowing 300g/sec of air, because the stock MAF sensor (which the UTEC still uses for fueling) is pegged. 300 or 400 grams, the MAF reading would be the same at 4.9v or so.

when's the last fuel filter change?

Make sure you have the FCD switch flipped away from the main UTEC connector. If you don't the stock ECU will try to cut the duty cycle on the fuel pump when you run above 20psi of boost.

-Nathan
www.turboxs.com
i was having a similar issue...and then i flipped the FCD switch to the correct position, and everything is gravy now.

have you actually re-tuned for the new MAF? unless you have compensated for what the ecu will think the airflow really is, you will run lean.

Last night I went out and checked the FCD switch, fliped it a few times, rotated the map selector switch, and unplugged the utec and let it sit for a while and pluged everything back up.

Today I went out and made some logs and adjustments. I didn't make any significant changes to the fuel map, mainly added some boost and timing. Everything looks good today.


3171 -7.3 2.3 15 00 00 +45.2 10.4 ECU. +0.0 500.00 2.1 14.37
3217 -7.1 2.5 27 00 00 +45.5 13.5 ECU. +0.0 500.00 2.6 14.45
3267 -5.3 2.8 53 10 00 +40.8 18.5 +27.5 +4.5 500.00 2.7 14.78
3300 -3.4 3.0 80 10 00 +35.2 19.9 +26.9 +4.3 500.00 2.8 13.68
3394 -1.2 3.0 97 10 00 +35.0 21.5 +26.0 +4.0 500.00 2.9 12.18
3450 +1.3 3.1 98 10 00 +34.7 22.9 +25.1 +3.7 500.00 3.0 11.37
3516 +2.3 3.2 98 20 00 +33.1 26.4 +21.5 +4.4 500.00 3.0 11.23
3580 +3.7 3.2 98 30 00 +31.5 28.2 +21.3 +2.0 500.00 3.1 11.06
3663 +5.3 3.3 98 30 00 +31.7 29.3 +21.1 +1.6 500.00 3.1 10.87
3770 +6.8 3.5 98 40 00 +29.6 32.1 +21.0 -0.6 500.00 3.3 11.18
3849 +8.6 3.6 99 40 00 +27.7 34.6 +21.0 +0.1 500.00 3.3 11.43
3982 +10.2 3.8 97 50 00 +25.7 40.6 +20.0 -0.5 500.00 3.5 11.48
4095 +12.1 4.0 98 60 00 +22.7 45.8 +20.0 -0.2 500.00 3.6 11.62
4273 +15.1 4.1 98 80 00 +20.5 50.4 +19.5 -1.1 500.00 3.7 11.65
4357 +17.6 4.2 97 90 00 +17.6 55.8 +20.8 -1.0 500.00 3.9 11.56
4578 +20.4 4.4 97 100 00 +17.9 61.9 +21.0 -1.1 500.00 4.0 11.58
4755 +22.7 4.4 97 100 00 +19.0 67.2 +21.0 -2.2 500.00 4.0 11.56
5020 +23.7 4.4 98 100 00 +21.1 69.6 +21.0 -2.5 500.00 4.0 11.56
5120 +24.3 4.5 98 100 00 +22.5 70.7 +21.1 -3.0 500.00 4.0 11.43
5151 +24.1 4.5 98 100 00 +23.2 70.1 +21.5 -3.4 500.00 4.0 11.33
5491 +23.7 4.5 97 100 00 +24.5 70.6 +21.5 -3.4 500.00 4.0 11.43
5602 +23.1 4.5 99 90 00 +24.3 67.4 +21.5 -3.5 500.00 4.0 11.49
5757 +22.5 4.5 98 90 00 +24.3 69.9 +21.5 -3.5 500.00 4.0 11.62
5847 +21.9 4.6 98 90 00 +24.7 71.7 +21.6 -3.5 500.00 4.0 11.73
5973 +21.5 4.6 98 90 00 +27.9 73.5 +21.9 -3.5 500.00 4.1 11.73
6105 +21.9 4.6 97 90 00 +28.7 72.9 +22.0 -3.5 500.00 4.1 11.73
6207 +21.7 4.6 98 90 00 +29.1 76.8 +22.0 -3.5 500.00 4.1 11.77
6485 +21.7 4.6 98 90 00 +29.3 77.1 +22.0 -3.5 500.00 4.1 11.73
6574 +21.9 4.6 97 90 00 +29.3 76.1 +22.0 -3.3 500.00 4.1 11.68
6510 +21.7 4.6 98 90 00 +31.4 77.8 +22.5 -3.2 500.00 4.1 11.71
6958 +22.3 4.6 98 100 00 +32.5 73.0 +22.5 -3.2 500.00 4.1 11.77
7032 +22.1 4.7 96 90 00 +32.3 72.5 +22.5 -2.7 500.00 4.2 11.92
6373 +18.6 2.5 0 00 00 +39.4 23.9 ECU. +0.3 LCM. 3.7 12.61
5889 +10.2 3.6 0 00 00 +39.5 36.7 ECU. +0.0 LCM. 3.2 22.06
5402 +0.8 3.3 0 00 00 +42.1 27.2 ECU. +0.0 LCM. 2.9 >25:1
5012 -7.5 3.0 0 00 00 +22.7 20.8 ECU. +0.0 500.00 2.7 >25:1
4642 -12.8 2.8 0 00 00 +22.9 31.8 ECU. +0.0 500.00 2.5 >25:1
4257 -13.4 2.7 0 00 00 +22.9 31.8 ECU. +0.0 500.00 2.4 20.65

I am starting to think my utec has some issues. The problems I have are completely intermitant and these are some of them. 1) Miss fires on cold startup, car will start fine, drop a cyl for about 3 sec and then the cyl will come back. Have had two different types of plugs in the car and about every plug gap combo you can get, the miss still occurs to random cyls. sometimes it will be cyl 1, sometimes cyl 2, ect. 2)If I am looking at the dash screen, the mode will sometimes switch from what ever map I have selected with the remote switch, to stock, then back to the map #. 3)At idle AFR will fall through the bottom, normal idle 14.7, then will fall to 9.7-10.5 unless I turn off the car or drive for a while. Do I have a problem with my utec, or am I just overlooking some other problem.