EDIS-8 Problem

[speeder]

I got the LT-1 all ready to go with Megasquirt 1/V3.0/MSNS/EDIS - and all it does is sometimes fire once, then nothing when attempting to start. I'm using a Cadillac northstar DIS coil pack with the ignition modue removed and bypassed.

 

Scoping the PIP signal, on the first couple revolutions of the starter there's a good square 12v pulse, then it goes to a ragged looking negative - going spike pulse from 12V to ~ 6v. The coils spark once when the the starter is disengaged, sometimes once on the first crank. Megatune shows an rpm signal for about 4 seconds, then goes to zero.

 

Disconnecting the spout connector in the PIP/SAW line makes no difference in the scoped signal.

 

Power to the EDIS module remains present during cranking, and the VR signal is present at the EDIS's VR + input. ( I did try swapping the sensor leads with negative improvement.)

 

I swapped in another EDIS-8 module with the same results.

 

Disconnected the coils and Megasquirt from the EDIS with the same results.

 

The only thing strange I see is that I have some runout on the trigger wheel and the amplitude of the VR signal is varying about 20% as a result. Even at the lowest amplitude the VR signal is at least 3 Volts peak - to - peak.

 

I'll be getting that trigger wheel runout fixed, and will double (and triple) check my wire connections, but does anyone have any insights they might pass on? Any help would be greatly appreciated. I've done two EDIS -6 installs with no problems - and expected none from this POS, and it will be called that until it works!

 

I'm taking the long weekend off from this disgusting problem, and will be back on it with (hopefully) a fresh outlook next week.