at lower voltages the paules with is higher 132 to 137 blms higher voltage paulse with is lower an makes blms go up to 150 or more.

paulse with vs battery voltage, on a 288 ecm at 11.2 volts paulse with is 1.063, at 14.4 volts it is 0.984 that will change blms a lot. I don't know what it is on a 7747.

bad ecm ?