Manual engine startup on stock 737?

Hello all,

I am trying to do the manual engine start on the FSX stock 737 - just don't want to press CTRL-E to start up the plane.

So, I start battery power, get the APU running, and turn on the engine (move the cutoff level [under the throttle] up) - then repeat for engine 2

The engines start up fine, but on my flight display, they both display "START VALVE OPEN" - when I do the CTRL-E, that message disappears when the engines spin up for a second. When I do it manually, I can't get rid of it!

Nor can I find any "start valve" control to close them...the fuel pumps are off, everything else looks good - is this something MS forgot to put a switch for on the panels? Any advice? I will eventually be buying some PMDG craft when they finalize the FSX versions, but wanted to get a head start by boosting my realism a tiny bit. Any one with a checklist or instructions pertaining to the stock 737 - you're a lifesaver!