Okay, sorry if this is off topic... but it is still relevant to MS users...

I got the issue all sorted out in this thread:

http://www.msextra.com/forums/viewtopic.php?f=132&t=50803

Basically, your main relay should not power up everything right from the ignition switch, if you do that, and your main ECU fuse blows or is removed, the injectors and coils can get shorted to ground through the PNP transistors they use.

So, the fuel pump relay output uses an NPN transistor, which will not allow ground connection through the ECU if the ECU loses power.

Symtechlabs has it right on the 420a schematic, so make it match that and you'll be fine.

If you switch everything on with one relay, just don't remove the power to the ECU with they key on or you could toast your injectors.

In summary:

Power ECU from key switch. It will enable the fuel pump relay. Power everything else using the 12v power that comes out of the fuel pump relay. (Ideally this would be just powering up your 'main' relay... in essence making it less 'main' than once intended.)