I'm about fed up w/ Megasquirt

[trwebb26]

I have a v3.0 board running MS&SE. Everything works fine except spark output. I started out having the VB circuit drive an MSD 6a - to an MSD blaster 2 coil - to the 83' optical dizzy. The car responded very well for a few minutes, but would then start ignition misses and die. If you want a few minutes - it would start back up and run fine. There are several other who have had this problem that I've found on this forum and others.

 

After a bunch of searching - I figured out that I don't even need to use the VB circuit to trigger the msd box... I could just run off of the negative side of the D14 diode. I rewired the megasquirt - removing Q16 (the IGBT coil driver) and now the car don't respond like it is supposed to. I know that I'm getting spark because I CAN start the car... but the timing is WILDLY off - and it only runs on a few cylinders. My wideband O2 reads nothing but 10's (the minimum reading) and there are big puffs of atomized gas coming out of the tailpipe... It smells like raw gas BAD.

 

So I guess the good part is that I'm getting SOME spark. I've tried inverting the spark output, checking for cold-solder joints on the board, messing with the settings in megasquirt, several dwell settings (it is currently set at fixed-50%). At this point I don't know if I'm missing one little thing in the software, if my board is wired wrong, something is fried in the board, or what is going on. I'd appreciate any troubleshooting ideas as I'm about tapped out. Thanks!

[mobythevan]

but the timing is WILDLY off

 

so that means that you cannot get timing set correctly when you follow the setup procedure? Set fixed timing to 10 degrees and then use a timing light to set it to 10 degrees. So it always moves on you? Can't be set to 10 because you cannot turn the trigger source far enough? OR trigger angle is setup wrong?

 

From reading the post it sounds like you made the circuit change and expected timing to fall into place without having to be set again.

 

I am just trying to decipher where you are at and what you have done to set up the timing correctly.