peak-n-holds

[Mike Pitts]

>So to change to Peak+Holds was just a simple R+R of the transistors?.
>I was under the impression that it took a "board" with at least a sense
>resistor, and some support electronics

It wasn't that simple, but close.

For these particular drivers, a sense resistor is not required. 
They are the same type of driver as the Motorola MC3484S4-2. 
It's a rather self-contained driver, with the only external additions 
being a resistor on the supply voltage and a zener between the 
output and ground.

On the 1227148, there's already a zener in the original circuit, 
shared by all the drivers, isolated by other diodes.  I had to find 
a source for the supply voltage, but that was easy by just following 
a trace and double checking with a meter.

I installed my brand new completely modified ECM a few minutes 
ago and the car fired right up.  Is it possible that the car would idle 
smoother from this change, or am I just imagining things? I'm 
thinking that at the super low pulsewidths required for these big 
injectors at idle, the flow is more uniform with the peak current 
yanking them open harder than the saturation drivers did...just 
a guess.

-Mike