MSD 6a, Dwell Settings, & Trigger Angle Problems

[trwebb26]

I have MS v3.0 hardware running MS&SE. It is on a 78' 280z with an MSD 6a ignition module fired via pin 36.

I was having some problems with my setup... It wouldn't rev over 2500 rpm without the engine poping, running like crap, and other such things. On further discovery - the timing was climinbing VERY high (+40 BTDC) at these low RPM values... not what was in my spark table.

After some reading... I decided to play with my dwell settings. Once I set the dwell to fixed (for the MSD) and set it to "minimal" - the engine really came alive!!! The idle calmed down, it ran smoother, and it revved all the way up the RPM range. The first time it had done it in 6+ months!

Needless to say I was pretty excited about this. Since I had it out - I put a timing light on it and the timing was off? I adjusted the trigger angle up and down (from 50 to 80 degrees) and the timing did not change (the fixed angle was set to -10 degrees). I tried revving the engine - and the timing mark did not move.

This is my current problem. I'm wondering if the MSD is causing complications with the timing. How should the dwell be set up for an MSD 6a? What can I try to fix my timing so it will read from the spark map?

Thanks!
Tim

[shaodome]

Duty Cycle with the MSD should be fixed at 75% and make sure your spark output is inverted. MSD triggers when the whit wire (if that is what your using) is REMOVED from a ground.