Miata Spark help... jumpy CAS signal

AlHounos · Post by **AlHounos** » Sun May 14, 2006 12:10 pm

V3 board MSnSE 029j

I've done the DSM input and output mods, and the car has been running great on fuel only using the CAS for RPM signal. But when I connect spark, the car backfires and barely idles on two cylinders, like the timing is WAY off. I noticed the Tach on megatune jumps around wildly (from 0-8000rpm) when it is "idling" like this. It worked fine when it was on fuel only.

I have not changed any MSQ settings. The only thing I have changed is to connect the ignitor output wires to the ignitor.

Thanks a bunch!

AlHounos · Post by **AlHounos** » Mon May 15, 2006 4:56 pm

I just noticed DIYautotune's instructions have changed again. It now specifies 2 470ohm resistors on the input mod instead of all 3 being 1000ohm.

Could this be the problem? I've got some 330s laying around, should I put them in?

Reverant · Post by **Reverant** » Wed May 24, 2006 6:05 am

Any luck there Al? Do you have an optical-type CAS (flat back, 90-93 Mk1) or magnetic CAS (round back, 94-97 Mk1)?

Dimitris