Mark_ZZ3

In Winbin, when reading the values for Injector Pulse Width Correction vs Battery Voltage:

Volts - usec added
16.0 - 16
14.4 - 21
12.8 - 30
11.2 - 41

What do these translate to in milliseconds? Are these microseconds?

I am just trying to figure out a percentage difference these make at idle, for example if my pulse width is 1.2 ms.

Mark.

Low C1500

uses is microsecs. At higher voltage the injectors will reach fully open faster, and vice versa. However this table is pretty stupid cause your voltage sould always be the same 13.9 to 14.3 volts. If its not you got alternator probs.

JPrevost

And when you have alternator problems wouldn't it be nice that the vehicle still drove to where it could be fixed .
Does anybody know if there is an internal voltage regulator for the injectors on c3 or p4 ecm's? Or is that just for the sensors?

Mark_ZZ3

You are correct ... I do have some charging issues which could be contributing to an idle condition. Hence my question on the impact of a voltage change.

I know I could just replace the battery or alt, but I enjoy understanding the cause and effect. I should probably just watch survivor instead ... :-)

Mark.

RBob

iTrader: (1)

No voltage regulators for the injectors. The PnH's are current regulated.

Also need voltage correction during crank, vehicle voltage can really dip down.

RBob.

JPrevost

I needed the voltage correction not only during crank but in an emergency. A few years ago I was driving out to Ohio on the turnpyke, construction 2 lane NO SHOULDER, going through the tunnels near Harrisburg, 8pm (dark), raining.... my radio turns off. (hmm.. what the..) quickly look at volts, below 8!. Ah....crap hope I don't die from the big rigs cruising 60+. Quickly turn off winshield wipers and headlights keeping parking lights on. Car is sputtering from not enough voltage to jump the spark plug gap. Car is running on 6 maybe 4 cylinders at most and only half the time. Lucky for me I find an emergency pull over. The story is longer but let's just end here with a thank *** for GM alternators being so universal between models. Fixed in 15 minutes at yokal "no shirts/shoes needed" Texico and back on my way. Get to school, fix loose wires (cause of alternator death).
So for me, it wasn't the injectors, thank *** for that code or I wouldn't be here today!

Low C1500

Im sure the blm would take care of the voltage changes, to keep the motor running in a normal state. My original 89 alternator just went last week, and the motor ran just fine. I attribute that to the voltage correction table, and not the blm .