Haha, don't be amazed until I get it to work!

You know the 3500 has provisions for a distributor.

Got to work on the MS today. I loaded the new firmware (MS2Extra) and loaded the new tuning software on the computer (TunerStudio). I spent a good bit of time transferring settings from one program to the other. Then I got to work building some of the circuits. I can't finish all of the board modifications until I test the current GMDIS setup with the new firmware and software. Hopefully I can test it this weekend. After that, I can finish the rest of the board modifications and install the coil near plug ignition. ---stoked---

Some pictures of the cam input circuit I built.







The lead thats sitting there not being used runs to JS10 for input to the processor. I'll run it after I test the DIS.

Here is the wiring diagram for the factory CNP ignition on the LX9.


Pin A B and C are spark inputs to drive the coils. Pin D is sensor ground back to the Megasquirt, Pin E is block ground and F is 12V with a 15A fuse.

15A fuse? How much power is necessary to make it to the spark voltage?

It'* a 15A fuse on the factory setup So hopefully I won't pull more than that or I've got a problem.

No, I certainly hope not. I thought it was less. Isn't the spark several tens of thousands of volts AC at low amps? Also, if you're thinking of a reason to say the new setup pulls more power, somehow the factory ignition setup from GM may be more efficient at converting voltage than an aftermarket setup. I wouldn't bet on it, but there'* something to chew on.

Also, thanks for the additional chart! This thread is just loaded with info!

Yep, I did a lot of research in this CNP thing. I'm trying to cram as much information in this thread as possible. That way if somebody comes across this someday and want'* to do the same mods, they'll know exactly what to do.

It'* a pretty good idea! You've got a great start with these few 22 pages so far.

Alright, the pullup circuits for the coils are built but not wired in. That finishes the circuits that need to be built. In the proto area I now have added 1 input circuit for the cam sensor, and 3 outputs for direct control of 6 coils in wasted spark.

The engine fired on the new code. Now to finish the board modifications and pull the DIS and external crank trigger off.