I spoke to using mine to identify a bad ECU, and couldn't remember the
details, but it came to me later. That montor receives signals from 7
differen points and puts out 2. The output is coil pulse and injector
pulse. I failed to get a coil pulse . That told me immediatey that I had a
fault with the ECU. Changed out the ECU and it started instantly. It saved
me a huge amount of time digging, disconnecting and testing. That's what
it's all about.

But, like David B and Darrel Boehler said, it CAN all be done with a meter
if you want to spend the time and want more specfic data. Myself, I'm not
into it that deep.

Identifiy it, fix it, get on with it! Thats me.

John