I can't get pulse width low enough on siemens/mototron 60lb injectors

[ryans1000]

I have Mototron/siemens 60lb injectors on a stock ls1 motor with turbo. My wot and cruise tune with them is pretty good except for a rich idle at about 12:1 afr.

I have my all my injector tables setup for these injectors. I can't seem to get my injector pulsewidth down below 1.8. I keep lowering my ve table for the idle cells for testing, its way low around 15-20 now. But the pulse width will not go any lower . I could start hacking the b3701 and b4005 tables but it seems like the pulse widths should be able go lower with these setting. How is pulse width calculated? Any suggestions?


Here is what my tables look like

b4006 small pulse threshold is at 3.997

b3701 Injector Pulse Width Voltage Adjustment
Battery Volts {link: GM.VOLTS}
12.0v 12.5v 13.0v 13.5v 14.0v 14.5v
0.68 0.607 0.53 0.47 0.41 0.34

b4001 injector flow rate table is at 9.2422 on all cells with vacuum/boost referenced regulator.

b4002 Injector voltage correction cells are all 1.0

b4003 and b4004 minimum pulse widths are set to .80 .

b4005 Small Pulse Adjust (Milliseconds)
Milliseconds Value
0.000 0.121580
0.061 0.106383
0.122 0.106383
0.182 0.106383
0.243 0.091185
0.304 0.091185
0.365 0.091185
0.426 0.091185
0.486 0.091185
0.547 0.091185
0.608 0.091185
0.669 0.075988
0.729 0.075988
0.790 0.075988
0.851 0.075988
0.912 0.075988
0.973 0.060790
1.033 0.060790
1.094 0.060790
1.155 0.060790
1.216 0.060790
1.277 0.045593
1.337 0.045593
1.398 0.045593
1.459 0.045593
1.520 0.045593
1.581 0.045593
1.641 0.030395
1.702 0.030395
1.763 0.030395
1.824 0.030395
1.884 0.030395
1.945 0.015198
2.006 0.015198
2.067 0.015198
2.128 0.015198
2.188 0.015198
2.249 0.000000
2.310 0.000000

[5.7ute]

Can you post a log? Include DYNCYLAIR_DMA, GM.VOLTS, GM.AFR & GM.INJFLOW to the log if not already selected.

[joecar]

Some people have gotten large injectors to flow small amounts by running a lower FPR pressure.

[5.7ute]

Some people have gotten large injectors to flow small amounts by running a lower FPR pressure.

With those injector settings he should at least be able to get the pcm to command a smaller pw. Which for some reason isnt happening in this case. The 60lb motrons, from the info I have should be fine as low as 1.4-1.5ms.
Hopefully, by getting the necessary pids in a log file we should be able to see what is going on.

[Chuck L.]

Some people have gotten large injectors to flow small amounts by running a lower FPR pressure.

was thinking, too.
At 58psi, the Motos are flowing 69.28pph.

[joecar]

5.7ute, I looked thru some threads, you're right, he should be able to get down a bit more...

[5.7ute]

5.7ute, I looked thru some threads, you're right, he should be able to get down a bit more...

I am not sure how low I got mine on the old motor, I will have to see if I still have some old logs but I reckon they got nasty at around 1.3ms.

[ryans1000]

Thanks. I will do another log tonight and post it.

[ryans1000]

Here is the two uploads. Let me know if you need anything else. This is the first time someone has looked at my self taught tune/logs so let me know if you see anything wierd.

My signature has some of my setup details

Log_0031.efi

ryans_ibpw.pid

sdAutoVe_0021.tun

[5.7ute]

Very strange.
Going from your reported idle airmass of 0.03g/cyl , the pcm should be commanding around 0.8ms IBPW. (This is including the modifiers). Its like the minimum & default PW havent taken.
Have you read the tune from the pcm & verified it went through. Also there is a couple of out of range tables that need fixing {B6619} & {B6620}
I will keep looking.