megasquirt no spark

[dan catalyst]

ive got a no spark problem with my megasquirt.when i test it with a plug,i get one spark on the first rotation,then nothing.it wont kick over or anything,feels like the spark is dead.i feel like it isnt getting a signal from the cas,but i know the ecu is because it turn on the fuel pump,wich i understand to come on w/ rpm signal.the car ran on stock ecu,so the cas must have been working then.i am completely new to megasquirt and appeciate any help with this issue.thanks!
dan

 

[mobythevan]

You can verify that Megasquirt is getting a signal from the CAS by opening Megatune and looking at the RPM gauge while cranking over the engine.

 

[dan catalyst]

uggh,ok i fought a battle and got a cas signal,but it wont crank.i used the 1600cc msq from the database and verified that it would work with my setup,so its back to the basics of checking everything.im getting a backfire every once and a while on key on,so i know its got spark and fuel,plus i checked with a noid light and checked for spark.im sure its something stupid,i will post back when i find it.

 

[mobythevan]

I think the manual says to wire the coil power to come on with the fuel pump. Otherwise if the coils have power with key on, the megasquirt is just getting powered on and the coil trigger wires are unknown for the 1st split second which causes backfires. I had the backfire problem with another car and changed to power the coils from the fuel pump relay and that fixed the problem.