Injector DC Questions

[Calan]

I've read a lot about injector duty cycles, etc. but I'm a bit confused.

MMCd shows injector pulse values which usually read between 1.5ms and 7.0ms under normal driving up to maybe 3500 rpm. They go into the low 20ms area when I attempt a WOT pull.

What should I see here? How can I use these values to determine if I'm having serious issues with my MAFT/GM MAS and 650cc injectors?

My car runs like fried ass at the moment, and I'm guessing my injector/air/fuel settings are hosed. I've got a WB o2 coming soon which will hopefully help.

Here is a typical log:

TIMA FTRH FTO2 O2-R TPS MAFS RPM KNCK INJP
08° 102.2% 099.8% 0.00V 10.6% 0037.7Hz 1281 00 00.00ms
08° 102.2% 099.8% 0.00V 19.2% 0062.9Hz 1281 00 02.82ms
22° 102.2% 099.8% 0.00V 20.4% 0113.2Hz 1313 00 03.33ms
22° 102.2% 099.8% 0.02V 20.8% 0113.2Hz 1344 00 03.33ms
23° 102.2% 099.8% 0.02V 20.8% 0100.6Hz 1313 00 03.33ms
25° 102.2% 099.8% 0.02V 10.6% 0106.9Hz 1344 00 02.56ms
16° 102.2% 099.8% 0.04V 10.6% 0062.9Hz 1906 00 01.54ms
27° 102.2% 099.8% 0.02V 10.6% 0044.0Hz 1875 00 01.28ms
33° 102.2% 106.1% 0.00V 19.6% 0075.5Hz 1781 00 02.30ms
34° 102.2% 117.8% 0.00V 22.4% 0132.1Hz 2063 00 02.82ms
34° 102.2% 133.4% 0.02V 28.6% 0176.1Hz 2031 00 04.10ms
31° 102.2% 150.5% 0.21V 29.4% 0213.9Hz 2188 00 04.35ms
31° 102.2% 135.7% 0.82V 30.2% 0226.4Hz 2281 00 04.35ms
31° 102.2% 117.0% 0.64V 30.6% 0245.3Hz 2406 00 04.35ms
31° 102.2% 124.0% 0.62V 30.6% 0257.9Hz 2563 00 04.35ms
32° 102.2% 138.8% 0.72V 30.2% 0283.1Hz 2688 00 04.61ms
33° 102.2% 116.2% 0.80V 29.0% 0283.1Hz 2813 00 04.35ms
34° 102.2% 106.1% 0.21V 28.6% 0276.8Hz 2969 00 04.10ms
35° 102.2% 134.2% 0.76V 28.2% 0270.5Hz 3063 00 03.84ms
36° 102.2% 135.7% 0.29V 27.8% 0276.8Hz 3156 00 03.84ms
36° 102.2% 124.8% 0.14V 26.7% 0276.8Hz 3281 00 03.58ms
38° 102.2% 115.4% 0.72V 26.3% 0257.9Hz 3375 00 03.58ms
39° 102.2% 130.3% 0.80V 26.3% 0257.9Hz 3469 00 03.33ms
40° 102.2% 120.1% 0.12V 25.9% 0257.9Hz 3531 00 03.33ms
40° 102.2% 113.9% 0.76V 25.9% 0264.2Hz 3563 00 03.07ms
40° 102.2% 099.8% 0.14V 25.5% 0251.6Hz 3625 00 03.07ms
40° 102.2% 122.5% 0.72V 25.5% 0257.9Hz 3688 00 03.07ms
40° 102.2% 095.9% 0.72V 25.5% 0251.6Hz 3750 00 02.82ms
40° 102.2% 106.1% 0.88V 10.6% 0088.1Hz 3750 00 01.28ms
40° 102.2% 099.8% 0.92V 10.6% 0050.3Hz 3469 00 01.28ms
40° 102.2% 099.8% 0.90V 22.7% 0081.8Hz 3219 00 02.56ms
38° 102.2% 109.2% 0.02V 36.5% 0295.6Hz 2906 00 04.86ms
32° 102.2% 136.5% 0.64V 37.6% 0301.9Hz 2563 00 05.38ms
30° 102.2% 115.4% 0.78V 35.3% 0327.1Hz 2656 00 05.12ms
30° 102.2% 093.6% 0.64V 29.8% 0301.9Hz 2719 00 04.61ms
32° 102.2% 113.9% 0.23V 27.8% 0276.8Hz 2750 00 04.35ms
33° 102.2% 124.8% 0.12V 27.5% 0270.5Hz 2813 00 04.35ms
34° 102.2% 116.2% 0.51V 27.5% 0264.2Hz 2875 00 04.10ms
34° 102.2% 130.3% 0.82V 27.5% 0276.8Hz 2906 00 04.10ms
35° 102.2% 105.3% 0.70V 27.5% 0270.5Hz 2938 00 03.84ms
35° 102.2% 127.1% 0.12V 27.5% 0270.5Hz 3000 00 04.10ms
35° 102.2% 111.5% 0.80V 27.5% 0270.5Hz 3031 00 03.84ms
35° 102.2% 120.1% 0.59V 27.5% 0270.5Hz 3094 04 03.84ms
33° 102.2% 118.6% 0.74V 27.5% 0276.8Hz 3125 04 03.84ms
34° 102.2% 121.7% 0.78V 27.8% 0270.5Hz 3156 03 03.84ms
35° 102.2% 135.7% 0.45V 27.8% 0276.8Hz 3219 00 03.84ms
36° 102.2% 124.8% 0.66V 27.8% 0276.8Hz 3250 00 04.10ms
37° 102.2% 126.4% 0.74V 27.8% 0276.8Hz 3281 00 03.84ms
37° 102.2% 132.6% 0.78V 27.8% 0283.1Hz 3313 00 03.84ms
37° 102.2% 104.5% 0.21V 27.5% 0276.8Hz 3344 00 03.58ms
38° 102.2% 139.6% 0.51V 26.7% 0264.2Hz 3375 00 03.58ms
39° 102.2% 119.3% 0.16V 25.5% 0245.3Hz 3406 00 03.33ms
39° 102.2% 124.0% 0.74V 25.1% 0245.3Hz 3438 00 03.07ms
39° 102.2% 123.2% 0.80V 24.7% 0245.3Hz 3469 00 03.07ms
39° 102.2% 110.0% 0.16V 24.7% 0232.7Hz 3469 00 03.07ms
39° 102.2% 120.9% 0.82V 24.7% 0232.7Hz 3500 00 03.07ms
39° 102.2% 096.7% 0.21V 24.7% 0226.4Hz 3500 00 02.82ms
39° 102.2% 119.3% 0.74V 24.7% 0226.4Hz 3531 00 02.82ms
39° 102.2% 110.0% 0.78V 24.7% 0232.7Hz 3531 00 02.82ms
39° 102.2% 099.8% 0.08V 24.7% 0232.7Hz 3563 00 02.82ms
39° 102.2% 095.2% 0.43V 24.7% 0226.4Hz 3563 00 02.82ms
39° 102.2% 117.8% 0.18V 25.1% 0232.7Hz 3563 00 03.07ms
39° 102.2% 102.2% 0.51V 25.1% 0245.3Hz 3594 00 03.07ms
39° 102.2% 096.7% 0.76V 25.5% 0251.6Hz 3594 00 02.82ms
39° 102.2% 092.8% 0.55V 54.9% 0383.7Hz 3625 00 05.63ms
32° 102.2% 099.8% 0.20V 87.5% 0528.4Hz 3719 00 07.17ms
24° 102.2% 099.8% 0.78V 87.5% 0912.1Hz 3875 28 15.36ms
09° 102.2% 099.8% 0.94V 87.8% 1081.9Hz 3969 28 16.38ms
07° 102.2% 099.8% 0.94V 87.8% 1176.2Hz 4125 27 17.15ms
07° 102.2% 099.8% 0.94V 87.5% 1220.3Hz 4125 27 18.43ms
08° 102.2% 099.8% 0.94V 87.5% 1377.5Hz 4188 26 19.20ms
08° 102.2% 099.8% 0.94V 86.7% 1409.0Hz 4250 26 20.48ms
08° 102.2% 099.8% 0.92V 85.9% 1534.8Hz 4313 25 22.53ms
08° 102.2% 099.8% 0.04V 85.5% 1157.4Hz 4375 25 13.06ms
14° 102.2% 099.8% 0.94V 69.0% 1289.5Hz 4313 24 10.50ms
18° 102.2% 106.9% 0.02V 10.6% 0125.8Hz 3969 07 01.28ms
40° 102.2% 099.1% 0.94V 10.6% 0069.2Hz 3781 00 01.28ms
40° 102.2% 099.8% 0.86V 10.6% 0056.6Hz 3469 00 01.28ms
40° 102.2% 099.8% 0.90V 10.6% 0037.7Hz 3188 00 01.28ms
39° 102.2% 099.8% 0.90V 10.6% 0044.0Hz 2906 00 00.00ms
26° 102.2% 099.8% 0.02V 10.6% 0037.7Hz 2500 00 00.00ms
25° 102.2% 099.8% 0.00V 16.5% 0056.6Hz 2156 00 01.79ms
37° 102.2% 111.5% 0.02V 25.9% 0163.5Hz 2500 00 03.33ms


Thanks

 

[Calan]

Hey... don't confuse me... I'm getting old and I'm tired

I meant to stay consistent with your example.

*******

Available time = 1/rpm *2 (2 crank rotations)

4250 rpm/60 = 70.83 rps

1/70.83 * 2=.0282 sec = 28.2 ms

IDC = IPW/available time = 20.48 ms/28.2 ms = .726 = 72.6%

*******

Thanks for the help.... I plugged this into my excel logs and my IDC's look really low... no WOT runs though, so maybe that is normal? Feel free to check my numbers and comment

Here is 1st through 3rd gear log, leaving stoplight at "normal" acceleration:


TIMA FTO2 O2-R TPS MAFS RPM KNCK INJP IDC

13° 156.8% 0.98V 10.6% 0025Hz 0844 00 01.54ms 01.08%
13° 153.7% 0.98V 10.6% 0025Hz 0813 00 01.54ms 01.04%
10° 150.5% 0.98V 11.4% 0025Hz 0781 00 01.79ms 01.17%
09° 148.2% 0.98V 11.8% 0025Hz 0781 00 01.79ms 01.17%
08° 145.1% 0.98V 12.2% 0025Hz 0813 00 01.79ms 01.21%
09° 142.0% 0.98V 13.7% 0031Hz 0844 00 02.05ms 01.44%
10° 138.8% 0.29V 14.5% 0050Hz 0938 00 02.56ms 02.00%
13° 141.2% 0.10V 14.9% 0063Hz 1281 00 02.56ms 02.73%
21° 150.5% 0.08V 14.9% 0075Hz 1625 00 02.30ms 03.12%
29° 150.5% 0.98V 14.1% 0075Hz 1844 00 02.05ms 03.15%
33° 139.6% 0.98V 12.5% 0057Hz 1844 00 01.54ms 02.36%
32° 126.4% 0.98V 12.5% 0044Hz 1688 00 01.28ms 01.80%
27° 116.2% 0.98V 12.5% 0038Hz 1469 00 01.54ms 01.88%
22° 112.3% 0.10V 12.5% 0038Hz 1281 00 01.54ms 01.64%
18° 118.6% 0.10V 12.5% 0038Hz 1125 00 01.79ms 01.68%
16° 125.6% 0.10V 12.5% 0038Hz 1125 00 01.79ms 01.68%
15° 131.0% 0.08V 12.5% 0044Hz 1125 00 01.79ms 01.68%
16° 138.1% 0.10V 12.5% 0044Hz 1156 00 01.79ms 01.73%
16° 138.8% 0.51V 12.5% 0044Hz 1156 00 01.79ms 01.73%
16° 131.8% 0.96V 12.5% 0038Hz 1156 00 01.79ms 01.73%
16° 125.6% 0.51V 12.5% 0044Hz 1156 00 01.79ms 01.73%
16° 128.7% 0.10V 20.0% 0063Hz 1156 00 03.33ms 03.21%
19° 136.5% 0.08V 20.8% 0132Hz 1531 00 03.84ms 04.90%
29° 149.0% 0.90V 21.2% 0138Hz 1688 00 03.58ms 05.04%
29° 134.2% 0.98V 21.2% 0138Hz 1625 00 03.58ms 04.85%
29° 120.9% 0.98V 21.2% 0138Hz 1656 00 03.58ms 04.95%
29° 106.1% 0.90V 21.2% 0145Hz 1594 00 03.58ms 04.76%
29° 094.4% 0.60V 21.2% 0138Hz 1531 00 03.58ms 04.57%
29° 082.7% 0.43V 22.7% 0164Hz 1781 00 03.84ms 05.70%
31° 099.1% 0.08V 23.1% 0182Hz 2000 00 03.58ms 05.97%
31° 095.2% 0.98V 24.3% 0208Hz 2281 00 03.58ms 06.81%
32° 074.1% 0.39V 25.1% 0226Hz 2500 00 03.58ms 07.47%
32° 100.6% 0.43V 25.1% 0245Hz 2750 00 03.58ms 08.21%
34° 085.0% 0.98V 25.1% 0252Hz 2969 00 03.33ms 08.23%
36° 061.6% 0.98V 12.2% 0151Hz 3000 00 01.28ms 03.20%
39° 099.8% 0.98V 10.6% 0038Hz 2750 00 01.28ms 02.93%
38° 099.8% 0.98V 14.9% 0031Hz 2438 00 01.54ms 03.12%
38° 094.4% 0.98V 27.1% 0208Hz 2188 00 04.35ms 07.93%
29° 110.0% 0.08V 33.7% 0270Hz 2156 00 05.38ms 09.66%
26° 106.9% 0.98V 34.1% 0277Hz 1969 00 05.38ms 08.82%
25° 092.0% 0.98V 34.1% 0289Hz 2094 00 05.38ms 09.38%
26° 072.5% 0.98V 34.1% 0315Hz 2281 00 05.12ms 09.73%
27° 049.1% 0.72V 34.1% 0333Hz 2438 00 05.12ms 10.40%
28° 060.1% 0.08V 34.1% 0365Hz 2594 00 05.38ms 11.62%
29° 086.6% 0.74V 33.3% 0384Hz 2813 00 05.38ms 12.60%
29° 060.8% 0.98V 28.2% 0371Hz 3000 00 04.35ms 10.88%
32° 032.8% 0.90V 25.5% 0340Hz 3125 03 03.58ms 09.33%
33° 035.9% 0.98V 21.6% 0277Hz 3219 00 01.79ms 04.81%
38° 032.8% 0.98V 10.6% 0044Hz 3094 00 01.28ms 03.30%
39° 099.8% 0.98V 10.6% 0031Hz 2719 00 01.28ms 02.90%
38° 095.9% 0.98V 30.6% 0226Hz 2594 00 04.61ms 09.96%
31° 104.5% 0.08V 36.1% 0346Hz 2688 00 05.38ms 12.04%
28° 103.0% 0.98V 34.9% 0321Hz 2250 00 05.38ms 10.08%
27° 081.9% 0.98V 33.7% 0333Hz 2406 00 05.12ms 10.27%
28° 060.1% 0.49V 33.3% 0340Hz 2500 00 05.38ms 11.20%
28° 082.7% 0.68V 30.6% 0340Hz 2563 00 05.12ms 10.93%
28° 060.8% 0.80V 30.2% 0352Hz 2625 00 04.86ms 10.64%
30° 061.6% 0.08V 29.8% 0359Hz 2719 00 05.12ms 11.60%
29° 070.2% 0.98V 29.4% 0359Hz 2781 00 04.61ms 10.68%
30° 052.3% 0.16V 28.2% 0346Hz 2844 00 04.61ms 10.92%
31° 077.2% 0.86V 27.1% 0340Hz 2938 00 04.35ms 10.65%
32° 048.4% 0.98V 26.7% 0327Hz 3000 00 03.84ms 09.60%
33° 045.2% 0.10V 25.9% 0315Hz 3000 00 03.84ms 09.60%
34° 055.4% 0.98V 25.1% 0289Hz 3063 00 03.33ms 08.49%
35° 049.1% 0.10V 24.7% 0270Hz 3094 00 03.33ms 08.58%
36° 073.3% 0.96V 24.7% 0258Hz 3156 00 03.07ms 08.08%
36° 058.5% 0.10V 25.9% 0264Hz 3156 00 03.33ms 08.75%
36° 089.7% 0.33V 26.7% 0289Hz 3188 00 03.58ms 09.52%
35° 074.9% 0.98V 26.7% 0302Hz 3250 00 03.58ms 09.71%
35° 047.6% 0.47V 27.1% 0308Hz 3281 00 03.58ms 09.80%
35° 074.1% 0.23V 28.6% 0333Hz 3313 00 04.10ms 11.31%
34° 073.3% 0.98V 30.2% 0371Hz 3375 00 04.10ms 11.52%
33° 065.5% 0.08V 30.2% 0384Hz 3406 00 04.61ms 13.08%
33° 085.8% 0.96V 30.2% 0396Hz 3500 00 04.35ms 12.69%
33° 079.6% 0.08V 30.2% 0409Hz 3563 00 04.86ms 14.44%
33° 094.4% 0.98V 29.8% 0409Hz 3625 00 04.61ms 13.92%
33° 064.7% 0.10V 29.8% 0415Hz 3688 00 04.86ms 14.95%
33° 090.5% 0.96V 29.8% 0421Hz 3750 00 04.35ms 13.60%
33° 090.5% 0.08V 29.4% 0421Hz 3813 00 04.61ms 14.64%
33° 088.9% 0.55V 29.4% 0421Hz 3875 00 04.86ms 15.71%
33° 106.9% 0.98V 29.4% 0421Hz 3969 00 04.35ms 14.39%
34° 067.9% 0.60V 27.5% 0384Hz 4000 00 03.58ms 11.95%
35° 095.2% 0.08V 27.1% 0359Hz 4063 00 03.84ms 13.00%
37° 088.1% 0.98V 27.1% 0340Hz 4063 00 03.58ms 12.13%
37° 099.8% 0.98V 28.2% 0333Hz 4125 00 03.84ms 13.20%
37° 099.8% 0.98V 29.4% 0377Hz 4094 00 04.10ms 13.97%
35° 099.8% 0.98V 29.8% 0403Hz 4188 00 04.35ms 15.19%
35° 099.8% 0.98V 30.2% 0415Hz 4219 00 04.35ms 15.30%
34° 099.8% 0.98V 30.6% 0428Hz 4313 00 04.61ms 16.56%
34° 099.8% 0.88V 30.6% 0434Hz 4375 00 04.61ms 16.80%
34° 099.8% 0.55V 29.0% 0428Hz 4313 00 01.79ms 06.44%
42° 099.8% 0.98V 10.6% 0069Hz 4031 00 01.28ms 04.30%

 

[steve]

I plugged this into my excel logs and my IDC's look really low.
No WOT runs though, so maybe that is normal?
Feel free to check my numbers and comment

I use IDC% = (IPW*((RPM/60)/2))/1000) in my spreadsheet with the cell formatted as percentages and IPW in milliseconds.

Spot checking your data matches.

Looking at your earlier log, once you started knocking your IDC's skyrocketed.

24° 102.2% 099.8% 0.78V 87.5% 0912.1Hz 3875 28 15.36ms 49.60%

07° 102.2% 099.8% 0.94V 87.8% 1176.2Hz 4125 27 17.15ms 58.95%
07° 102.2% 099.8% 0.94V 87.5% 1220.3Hz 4125 27 18.43ms 63.35%

08° 102.2% 099.8% 0.92V 85.9% 1534.8Hz 4313 25 22.53ms 80.93%

 

[oldman]

Hey... don't confuse me

Let me clear it up for you.

The real formula is 1/frequency*2

Frequency, in this case, is meassure in revolution per minutes (RPM).

Dividing RPM by 60 gives you RPS (60 seconds in one minute)

Multiplying RPM by 60 gives you RPH (60 minutes in one hour)

We are converting to seconds for simplicity because your logger gives you IPW in ms(milli seconds)

Let's look at a couple of examples in your log.

13° 141.2% 0.10V 14.9% 0063Hz 1281 00 02.56ms 02.73%

1281 rpm / 60 = 21.35 rps
1/21.35 *2 = .0937 seconds = 93.7 ms (1s = 1000 ms)
2.56ms/93.7ms = .0273 = 2.73%

34° 099.8% 0.88V 30.6% 0434Hz 4375 00 04.61ms 16.80%

4375/60 = 72.92
1/72.92*2 = .0274 = 27.4 ms
4.61ms/27.4ms = .168 = 16.8%

Your IDCs are right on.

edit:beaten by steve.

 

[oldman]

Looking at your earlier log, once you started knocking your IDC's skyrocketed.

Steve, would that indicate boost leaks/rich knock?

 

[steve]

The real formula is 1/frequency*2

Frequency, in this case, is measured in revolution per minutes (RPM).

Dividing RPM by 60 gives you RPS (60 seconds in one minute)

Multiplying RPM by 60 gives you RPH (60 minutes in one hour)

We are converting to seconds for simplicity because your logger gives you IPW in mS (milli Seconds)

Technically the formula for period (mS) is 1/frequency (Hz) T = 1/f

We multply the period by 2 since the 4 cycle engine fires a cylinder every other revolution.

In my formula I divide the frequency in half which give us the same result.

Steve

 

[oldman]

Available time = 1/rpm *2 (2 crank rotations)

 

[Calan]

Looking at your earlier log....

The log I just posted was after I got the WB hooked up last night, and was able to get my base setup dialed in a bit closer. Those previous logs were WAY out of whack.

I updated the MMCd Tools excel template to give me a new formatted IDC column, as well as an AFR column. (The Tools software logs the EGRT internally, so it doesn't transfer correctly... but a new Excel column reading the raw values will work.)

Now that I have IDC values, how can I use/modify them with my setup? Should I be looking at something in the logs and adjust my fuel pressure? I've heard of some guys raising it, and others drop it. Mine's staying stock 38 until I know why I should change it

Thanks

 

[Calan]

Steve, would that indicate boost leaks/rich knock?

I'm pretty sure it was rich knock... my O2 sensor was hosed, and previous to the WB it was a shot in the dark on the MAFT.

Boost leak tests showed good after I rebuilt the TB last weekend.

 

[steve]

Now that I have IDC values, how can I use/modify them with my setup? Should I be looking at something in the logs and adjust my fuel pressure? I've heard of some guys raising it, and others drop it. Mine's staying stock 38 until I know why I should change it

Thanks

Your going to tune based on your WB feedback to reach some AFR target at WOT. Adjusting your fuel pressure is one way to make changes in AFR across the board. Your going to use your MAFT, ECU Chip, SAFC to do the rest of your tuning. Once you start making changed with them you'll see your IPW change which will in turn cause the IDC to change. Usually your only looking at IDC to make sure that you haven't maxed out your injectors.

Steve

 

[Calan]

Your going to tune based on your WB feedback to reach some AFR target at WOT. Adjusting your fuel pressure is one way to make changes in AFR across the board. Your going to use your MAFT, ECU Chip, SAFC to do the rest of your tuning. Once you start making changed with them you'll see your IPW change which will in turn cause the IDC to change. Usually your only looking at IDC to make sure that you haven't maxed out your injectors.

Steve

No chip or SAFC

 

[Calan]

Here is a graph of a log (basically the same one previously posted... the graph is showing normalized values)

You must be logged in to view this image or video.

Can one or both of you guys take me through what is happening here, as far as how different parameters relate to each other, especially IDC? I know some of it, and some is obvious... I just want to make sure I understand as much as possible about what is causing what.

The markers along the bottom are the data collection points; there are 3 per second, with the whole log covering a little over 1 minute. This is from idle through 5th gear and then coast, at normal acceleration.

BTW - what is up with the spike at 143?

Below is the log data that the graph was created from.

Thanks as always!

***********************


DATA TIMA FTO2 TPS MAFS RPM IDC WBO2 KNCK

001: 09° 127.1% 10.6% 0025Hz 0813 01.2% 14.3 00
002: 09° 131.0% 10.6% 0025Hz 0813 01.2% 14.2 00
003: 09° 133.4% 10.6% 0025Hz 0813 01.2% 14.1 00
004: 08° 134.9% 10.6% 0025Hz 0813 01.2% 14.0 00
005: 08° 138.8% 10.6% 0025Hz 0844 01.3% 14.0 00
006: 08° 140.4% 10.6% 0025Hz 0844 01.3% 13.9 00
007: 09° 142.7% 10.6% 0025Hz 0875 01.1% 13.8 00
008: 09° 144.3% 10.6% 0025Hz 0875 01.1% 13.7 00
009: 09° 146.6% 10.6% 0025Hz 0906 01.2% 13.5 00
010: 10° 149.0% 10.6% 0025Hz 0906 01.2% 13.6 00
011: 10° 151.3% 10.6% 0025Hz 0906 01.2% 13.5 00
012: 11° 155.2% 10.6% 0025Hz 0906 01.2% 13.2 00
013: 10° 157.6% 10.6% 0025Hz 0906 01.2% 13.1 00
014: 11° 159.1% 10.6% 0025Hz 0906 01.2% 13.2 00
015: 11° 161.5% 10.6% 0025Hz 0906 01.2% 13.2 00
016: 11° 163.8% 10.6% 0025Hz 0906 01.2% 13.1 00
017: 12° 162.2% 10.6% 0025Hz 0906 01.2% 12.9 00
018: 10° 157.6% 10.6% 0025Hz 0906 01.2% 12.9 00
019: 11° 154.4% 10.6% 0025Hz 0906 01.2% 12.9 00
020: 12° 151.3% 10.6% 0025Hz 0938 01.2% 13.0 00
021: 12° 155.2% 10.6% 0025Hz 0938 01.2% 13.3 00
022: 10° 157.6% 10.6% 0025Hz 0938 01.2% 13.4 00
023: 11° 159.9% 10.6% 0025Hz 0969 01.2% 13.3 00
024: 10° 162.2% 10.6% 0025Hz 0969 01.2% 13.3 00
025: 11° 164.6% 10.6% 0025Hz 0938 01.2% 13.2 00
026: 13° 166.1% 10.6% 0025Hz 0938 01.2% 12.9 00
027: 13° 159.9% 10.6% 0025Hz 0875 01.1% 11.6 00
028: 13° 156.8% 10.6% 0025Hz 0844 01.1% 11.0 00
029: 13° 153.7% 10.6% 0025Hz 0813 01.0% 10.4 00
030: 10° 150.5% 11.4% 0025Hz 0781 01.2% 09.8 00
031: 09° 148.2% 11.8% 0025Hz 0781 01.2% 09.4 00
032: 08° 145.1% 12.2% 0025Hz 0813 01.2% 09.5 00
033: 10° 138.8% 14.5% 0050Hz 0938 02.0% 13.3 00
034: 13° 141.2% 14.9% 0063Hz 1281 02.7% 14.5 00
035: 21° 150.5% 14.9% 0075Hz 1625 03.1% 13.6 00
036: 29° 150.5% 14.1% 0075Hz 1844 03.1% 11.4 00
037: 33° 139.6% 12.5% 0057Hz 1844 02.4% 10.1 00
038: 32° 126.4% 12.5% 0044Hz 1688 01.8% 09.6 00
039: 27° 116.2% 12.5% 0038Hz 1469 01.9% 11.9 00
040: 22° 112.3% 12.5% 0038Hz 1281 01.6% 13.5 00
041: 18° 118.6% 12.5% 0038Hz 1125 01.7% 13.8 00
042: 15° 131.0% 12.5% 0044Hz 1125 01.7% 13.2 00
043: 16° 138.1% 12.5% 0044Hz 1156 01.7% 13.1 00
044: 16° 138.8% 12.5% 0044Hz 1156 01.7% 13.0 00
045: 16° 131.8% 12.5% 0038Hz 1156 01.7% 12.7 00
046: 16° 125.6% 12.5% 0044Hz 1156 01.7% 13.0 00
047: 16° 128.7% 20.0% 0063Hz 1156 03.2% 13.4 00
048: 19° 136.5% 20.8% 0132Hz 1531 04.9% 14.3 00
049: 29° 149.0% 21.2% 0138Hz 1688 05.0% 12.5 00
050: 29° 134.2% 21.2% 0138Hz 1625 04.9% 11.8 00
051: 29° 106.1% 21.2% 0145Hz 1594 04.8% 12.6 00
052: 29° 094.4% 21.2% 0138Hz 1531 04.6% 12.9 00
053: 29° 082.7% 22.7% 0164Hz 1781 05.7% 12.9 00
054: 31° 099.1% 23.1% 0182Hz 2000 06.0% 13.4 00
055: 31° 095.2% 24.3% 0208Hz 2281 06.8% 12.6 00
056: 32° 074.1% 25.1% 0226Hz 2500 07.5% 12.8 00
057: 32° 100.6% 25.1% 0245Hz 2750 08.2% 12.9 00
058: 34° 085.0% 25.1% 0252Hz 2969 08.2% 12.0 00
059: 36° 061.6% 12.2% 0151Hz 3000 03.2% 12.6 00
060: 39° 099.8% 10.6% 0038Hz 2750 02.9% 07.8 00
061: 38° 099.8% 14.9% 0031Hz 2438 03.1% 09.4 00
062: 38° 094.4% 27.1% 0208Hz 2188 07.9% 10.7 00
063: 29° 110.0% 33.7% 0270Hz 2156 09.7% 14.5 00
064: 26° 106.9% 34.1% 0277Hz 1969 08.8% 11.7 00
065: 25° 092.0% 34.1% 0289Hz 2094 09.4% 11.4 00
066: 26° 072.5% 34.1% 0315Hz 2281 09.7% 11.8 00
067: 27° 049.1% 34.1% 0333Hz 2438 10.4% 12.7 00
068: 28° 060.1% 34.1% 0365Hz 2594 11.6% 13.7 00
069: 29° 086.6% 33.3% 0384Hz 2813 12.6% 12.8 00
070: 29° 060.8% 28.2% 0371Hz 3000 10.9% 12.4 00
071: 32° 032.8% 25.5% 0340Hz 3125 09.3% 12.4 03
072: 33° 035.9% 21.6% 0277Hz 3219 04.8% 12.4 00
073: 38° 032.8% 10.6% 0044Hz 3094 03.3% 10.0 00
074: 39° 099.8% 10.6% 0031Hz 2719 02.9% 09.8 00
075: 38° 095.9% 30.6% 0226Hz 2594 10.0% 09.8 00
076: 31° 104.5% 36.1% 0346Hz 2688 12.0% 14.7 00
077: 28° 103.0% 34.9% 0321Hz 2250 10.1% 11.9 00
078: 27° 081.9% 33.7% 0333Hz 2406 10.3% 11.9 00
079: 28° 060.1% 33.3% 0340Hz 2500 11.2% 13.0 00
080: 28° 082.7% 30.6% 0340Hz 2563 10.9% 12.8 00
081: 28° 060.8% 30.2% 0352Hz 2625 10.6% 12.8 00
082: 30° 061.6% 29.8% 0359Hz 2719 11.6% 13.5 00
083: 29° 070.2% 29.4% 0359Hz 2781 10.7% 12.2 00
084: 30° 052.3% 28.2% 0346Hz 2844 10.9% 13.3 00
085: 31° 077.2% 27.1% 0340Hz 2938 10.7% 12.6 00
086: 32° 048.4% 26.7% 0327Hz 3000 09.6% 12.5 00
087: 33° 045.2% 25.9% 0315Hz 3000 09.6% 13.7 00
088: 34° 055.4% 25.1% 0289Hz 3063 08.5% 12.6 00
089: 35° 049.1% 24.7% 0270Hz 3094 08.6% 13.7 00
090: 36° 073.3% 24.7% 0258Hz 3156 08.1% 12.3 00
091: 36° 058.5% 25.9% 0264Hz 3156 08.8% 13.6 00
092: 36° 089.7% 26.7% 0289Hz 3188 09.5% 13.3 00
093: 35° 074.9% 26.7% 0302Hz 3250 09.7% 12.2 00
094: 35° 047.6% 27.1% 0308Hz 3281 09.8% 12.8 00
095: 35° 074.1% 28.6% 0333Hz 3313 11.3% 12.7 00
096: 35° 074.1% 28.6% 0333Hz 3313 11.3% 12.5 00
097: 34° 073.3% 30.2% 0371Hz 3375 11.5% 12.5 00
098: 33° 065.5% 30.2% 0384Hz 3406 13.1% 13.6 00
099: 33° 085.8% 30.2% 0396Hz 3500 12.7% 12.5 00
100: 33° 079.6% 30.2% 0409Hz 3563 14.4% 13.6 00
101: 33° 094.4% 29.8% 0409Hz 3625 13.9% 12.4 00
102: 33° 064.7% 29.8% 0415Hz 3688 14.9% 13.3 00
103: 33° 090.5% 29.8% 0421Hz 3750 13.6% 12.4 00
104: 33° 090.5% 29.4% 0421Hz 3813 14.6% 13.3 00
105: 33° 088.9% 29.4% 0421Hz 3875 15.7% 12.6 00
106: 33° 106.9% 29.4% 0421Hz 3969 14.4% 12.3 00
107: 34° 067.9% 27.5% 0384Hz 4000 11.9% 12.9 00
108: 35° 095.2% 27.1% 0359Hz 4063 13.0% 13.6 00
109: 37° 088.1% 27.1% 0340Hz 4063 12.1% 12.2 00
110: 37° 099.8% 28.2% 0333Hz 4125 13.2% 12.4 00
111: 37° 099.8% 29.4% 0377Hz 4094 14.0% 12.4 00
112: 35° 099.8% 29.8% 0403Hz 4188 15.2% 11.5 00
113: 35° 099.8% 30.2% 0415Hz 4219 15.3% 11.6 00
114: 35° 099.8% 30.2% 0415Hz 4219 15.3% 12.4 00
115: 34° 099.8% 30.6% 0428Hz 4313 16.6% 12.4 00
116: 34° 099.8% 30.6% 0434Hz 4375 16.8% 12.7 00
117: 34° 099.8% 29.0% 0428Hz 4313 06.4% 12.9 00
118: 42° 099.8% 10.6% 0069Hz 4031 04.3% 09.8 00
119: 41° 099.8% 10.6% 0031Hz 3500 03.7% 10.3 00
120: 40° 099.8% 20.8% 0107Hz 3219 05.5% 10.3 00
121: 38° 097.5% 25.9% 0245Hz 3250 09.0% 15.2 00
122: 38° 128.7% 31.0% 0315Hz 3250 11.8% 12.8 00
123: 34° 101.4% 31.8% 0359Hz 3281 11.9% 12.2 00
124: 33° 070.2% 30.6% 0371Hz 3313 12.0% 12.8 00
125: 33° 084.2% 30.2% 0384Hz 3344 12.1% 12.6 00
126: 32° 070.2% 29.4% 0390Hz 3375 13.0% 13.6 00
127: 33° 076.4% 27.1% 0371Hz 3406 10.9% 12.6 00
128: 34° 043.7% 24.3% 0296Hz 3406 08.7% 12.7 00
129: 37° 045.2% 24.3% 0277Hz 3438 08.8% 13.7 00
130: 38° 081.9% 24.3% 0264Hz 3438 08.8% 13.0 00
131: 39° 060.8% 24.3% 0258Hz 3438 08.8% 13.3 00
132: 40° 094.4% 24.7% 0258Hz 3438 08.8% 12.9 00
133: 39° 067.1% 24.7% 0264Hz 3438 08.8% 12.7 00
134: 39° 086.6% 25.5% 0270Hz 3469 09.6% 13.5 00
135: 39° 081.1% 25.9% 0277Hz 3469 08.9% 12.5 00
136: 38° 074.1% 26.3% 0283Hz 3469 10.4% 13.6 00
137: 38° 086.6% 27.1% 0302Hz 3469 10.4% 12.3 00
138: 36° 064.0% 32.5% 0371Hz 3469 13.3% 13.7 00
139: 33° 104.5% 36.1% 0428Hz 3500 16.4% 13.1 00
140: 32° 131.0% 36.9% 0478Hz 3563 17.5% 12.6 00
141: 30° 102.2% 36.9% 0547Hz 3594 22.2% 13.6 00
142: 27° 120.9% 36.9% 0698Hz 3625 31.7% 12.6 00
143: 25° 099.8% 36.9% 0868Hz 3688 37.0% 08.2 00
144: 24° 099.8% 36.1% 0811Hz 3781 35.5% 03.5 00
145: 25° 099.8% 35.3% 0799Hz 3844 31.2% 03.4 00
146: 27° 099.8% 32.2% 0522Hz 3875 17.4% 04.8 00
147: 27° 099.8% 32.2% 0522Hz 3875 17.4% 13.4 00
148: 31° 066.3% 31.8% 0465Hz 3938 16.0% 13.4 00
149: 32° 106.9% 31.0% 0434Hz 3906 16.7% 13.8 00
150: 33° 134.9% 31.0% 0428Hz 3969 15.2% 12.5 00
151: 34° 107.6% 30.6% 0421Hz 4000 16.2% 13.5 00
152: 34° 127.9% 30.6% 0421Hz 4000 15.4% 12.5 00
153: 34° 107.6% 31.0% 0421Hz 4031 16.3% 13.6 00
154: 34° 135.7% 23.1% 0365Hz 3969 10.2% 12.7 00
155: 40° 106.1% 18.8% 0164Hz 4063 05.2% 10.3 00
156: 41° 072.5% 14.5% 0094Hz 4031 04.3% 12.0 00
157: 41° 099.8% 12.5% 0057Hz 3938 04.2% 09.6 00
158: 41° 099.8% 11.4% 0031Hz 3969 04.2% 10.7 00
159: 41° 099.8% 10.6% 0025Hz 3844 04.1% 11.5 00
160: 41° 099.8% 10.6% 0025Hz 3500 03.7% 12.5 00
161: 40° 099.8% 10.6% 0025Hz 3000 00.0% 12.3 00
162: 26° 099.8% 10.6% 0025Hz 2656 00.0% 11.5 00
163: 25° 099.8% 10.6% 0025Hz 2250 00.0% 14.3 00
164: 24° 099.8% 10.6% 0031Hz 2719 02.9% 20.9 00
165: 36° 099.8% 11.0% 0025Hz 3000 03.2% 20.9 00
166: 39° 099.8% 11.0% 0025Hz 2969 03.2% 12.6 00
167: 39° 099.8% 11.0% 0025Hz 2938 03.1% 10.8 00
168: 39° 099.8% 11.4% 0031Hz 2938 03.1% 10.1 00
169: 39° 099.8% 11.8% 0031Hz 2938 03.1% 09.5 00
170: 39° 099.8% 11.8% 0038Hz 2906 03.1% 09.4 00
171: 39° 099.8% 11.8% 0038Hz 2875 00.0% 09.1 00
172: 26° 099.8% 11.8% 0038Hz 2844 00.0% 10.5 00
173: 26° 099.8% 12.2% 0038Hz 2844 00.0% 21.7 00
174: 26° 099.8% 12.2% 0038Hz 2844 00.0% 24.3 00
175: 26° 099.8% 12.2% 0044Hz 2813 00.0% 25.1 00
176: 26° 099.8% 12.2% 0038Hz 2781 00.0% 25.3 00
177: 26° 099.8% 12.2% 0044Hz 2781 00.0% 25.5 00
178: 26° 099.8% 12.2% 0044Hz 2750 00.0% 25.5 00
179: 26° 099.8% 12.2% 0038Hz 2750 00.0% 25.5 00

 

[steve]

IDC isn't the useful data item for logs or graphs except for looking to see if your maxing out the injectors. We want to look at the pulse width in logs and see it track the airflow and your AFR.

I can't explain the spike. What's the scale here since the MAF HZ will range from about 25Hz to 1606Hz where the stock ECU will clip the output over the datalogger interface.

Pretty much all the fuel related variables are based from the airflow per rev. From that the ECU figures out how much fuel to inject. So IPW should directly relate to the air going in.
The AFR in closed loop operation should be swinging around 14.7:1 so that it averages out.
When the throttle is closed the ECU will turn off the injectors during coasting so you'll see IPW go to 0 and the AFR go max lean.
Under open loop the ECU will use the programmed fuel maps and change based on rpm and load. The factory maps go as rich as 9.5:1.

 

[Calan]

Steve,

The numbers in the log are the ones coming straight out of MMCd via the ECU. I just created new columns and scaled them a bit to make the graph trends readable... but the actual numbers in the log are correct.

EDIT:

For trend purposes, the graph is showing MAFS/8... RPM/100... IDC*100... and FT02/10. Everything else is the actual value.

 

[BISHILVR]

Calan, I have seen compressor surge cause a spike similar to yours.

 

[steve]

Calan, I have seen compressor surge cause a spike similar to yours.

From that log I'm not sure he actually making any boost. If he is it's not much. Why would the compressor be surging?

Steve

 

[BISHILVR]

It does'nt neccesarily take alot of boost to cause compressor surge!

 

[Calan]

Steve is correct... max boost on that log was probably 4-6 psi just before shifts.

 

[steve]

I wonder if you injested some water. The spike between 142 and 145 has a matching spike in IDC (because the ECU thinks extra air is entering) and a dip in AFR which shouldn't be the case unless the really isn't extra air and the added fuel is causing the mix to be very rich. (it drops to 3.4:1 from 12:1)

Water hitting the hot wire would cause it to cool very quickly and fool the circuit into thinking a large mass of air is passing. If it wasn't water then perhaps the GM MAF is bad.

Steve

 

[Calan]

Interesting theory... there is some some snow and road grime flying around here.

Here is a more recent log; this one is a short "almost" WOT pull in 3rd. And I say "almost WOT " because the AFR immediately went WAY HOG rich, very similar to the spike in the other log. (Needless to say the car was bucking like crazy so I didn't stay in it). Check out data points starting around #44.

Keep in mind that I haven't tuned anything at WOT yet, but I'm doubting if I could lean this kind of AFR out with the MAFT if it's for real.

I logged INJP per your suggestion for this one.


# TIMA FTO2 TPS MAFS RPM KNCK INJP IDC WBO2

001. 34° 111.5% 25.1% 0214Hz 2500 00 03.6ms 07.5% 14.2
002. 33° 131.0% 25.1% 0214Hz 2500 00 03.8ms 08.0% 13.5
003. 33° 142.0% 24.3% 0214Hz 2500 00 03.6ms 07.5% 12.4
004. 33° 126.4% 23.9% 0208Hz 2500 00 03.3ms 06.9% 12.2
005. 34° 109.2% 23.9% 0201Hz 2500 00 03.6ms 07.5% 12.7
006. 34° 118.6% 23.5% 0208Hz 2500 00 03.6ms 07.5% 13.4
007. 34° 131.0% 23.5% 0208Hz 2500 00 03.3ms 06.9% 12.4
008. 34° 112.3% 23.5% 0208Hz 2500 00 03.3ms 06.9% 12.5
009. 34° 107.6% 23.5% 0208Hz 2500 00 03.6ms 07.5% 13.3
010. 34° 127.1% 23.5% 0201Hz 2531 00 03.6ms 07.6% 12.9
011. 34° 127.1% 22.4% 0195Hz 2531 00 03.1ms 06.5% 12.3
012. 35° 111.5% 20.8% 0170Hz 2500 00 02.8ms 05.9% 12.3
013. 36° 100.6% 20.0% 0151Hz 2500 00 02.3ms 04.8% 12.6
014. 36° 093.6% 19.6% 0138Hz 2500 00 02.3ms 04.8% 13.4
015. 36° 110.8% 19.6% 0132Hz 2500 00 02.3ms 04.8% 13.8
016. 36° 121.7% 19.6% 0132Hz 2500 00 02.3ms 04.8% 13.5
017. 37° 134.9% 19.2% 0126Hz 2500 00 02.3ms 04.8% 13.4
018. 37° 147.4% 19.2% 0126Hz 2500 00 02.6ms 05.3% 13.0
019. 37° 156.0% 19.2% 0126Hz 2469 00 02.3ms 04.7% 12.7
020. 37° 040.6% 12.2% 0057Hz 2063 00 01.3ms 02.2% 13.5
021. 37° 053.0% 12.2% 0057Hz 2031 00 01.3ms 02.2% 13.8
022. 37° 062.4% 12.2% 0050Hz 2031 00 01.3ms 02.2% 12.9
023. 37° 056.2% 10.6% 0044Hz 1969 00 01.3ms 02.1% 12.4
024. 35° 044.5% 10.6% 0038Hz 1750 00 01.3ms 01.9% 12.6
025. 37° 037.4% 10.6% 0031Hz 1563 00 01.3ms 01.7% 13.0
026. 31° 041.3% 10.6% 0031Hz 1313 00 01.3ms 01.4% 13.6
027. 26° 046.0% 10.6% 0031Hz 1125 00 01.3ms 01.2% 13.9
028. 23° 051.5% 10.6% 0031Hz 1000 00 01.5ms 01.3% 14.4
029. 21° 055.4% 10.6% 0031Hz 0938 00 01.5ms 01.2% 14.2
030. 19° 058.5% 10.6% 0031Hz 0875 00 01.5ms 01.1% 13.9
031. 19° 062.4% 10.6% 0031Hz 0844 00 01.8ms 01.3% 13.7
032. 17° 065.5% 11.4% 0031Hz 0844 00 01.8ms 01.3% 13.5
033. 10° 069.4% 15.7% 0044Hz 0781 00 02.8ms 01.8% 13.6
034. 09° 074.1% 21.6% 0107Hz 1219 00 03.6ms 03.6% 14.1
035. 27° 082.7% 22.0% 0176Hz 2313 00 02.8ms 05.4% 14.2
036. 37° 099.1% 22.4% 0164Hz 3156 08 02.3ms 06.1% 14.4
037. 35° 122.5% 23.1% 0176Hz 3156 00 02.8ms 07.4% 14.2
038. 38° 138.1% 27.8% 0233Hz 3156 00 04.1ms 10.8% 13.7
039. 35° 099.8% 70.2% 0371Hz 3219 00 05.6ms 15.1% 12.6
040. 32° 099.8% 84.3% 0403Hz 3281 00 06.1ms 16.8% 12.3
041. 31° 099.8% 86.7% 0478Hz 3344 00 07.2ms 20.0% 13.8
042. 29° 099.8% 87.1% 0598Hz 3438 00 09.7ms 27.9% 13.8
043. 26° 099.8% 87.1% 1076Hz 3531 00 20.2ms 59.5% 12.3
044. 15° 099.8% 87.1% 1321Hz 3656 00 22.5ms 68.6% 04.0
045. 15° 099.8% 86.7% 1434Hz 3781 00 22.8ms 71.8% 03.3
046. 16° 099.8% 86.3% 1516Hz 3813 00 24.1ms 76.5% 03.3
047. 16° 099.8% 86.3% 1302Hz 3781 00 14.8ms 46.8% 03.3
048. 19° 099.8% 81.2% 1510Hz 3875 07 23.8ms 76.9% 04.6
049. 14° 099.8% 22.0% 0855Hz 3719 07 02.6ms 07.9% 03.3
050. 31° 088.9% 10.6% 0132Hz 3281 00 01.5ms 04.2% 09.8
051. 40° 067.1% 10.6% 0069Hz 3031 00 01.3ms 03.2% 08.1
052. 39° 054.6% 12.2% 0057Hz 2844 00 01.3ms 03.0% 07.8
053. 39° 098.3% 21.6% 0120Hz 2875 00 02.3ms 05.5% 07.0
054. 38° 088.9% 22.7% 0182Hz 2875 00 02.8ms 06.7% 14.7
055. 36° 102.2% 22.7% 0195Hz 2844 00 03.1ms 07.3% 14.1
056. 36° 122.5% 23.1% 0195Hz 2875 00 03.1ms 07.4% 13.2