In order to prevent the dreaded BOG, I've decided to perform routine maintenance on the troublesome solenoid valve that causes all the fuss. I do this about once a year (usually before my annual track day at Hallett), and so far, the BOG has been kept at bay. Please note that I don't put many miles on my MSM, so you might want to consider doing this more often. I won't guarantee that it will solve the problem for you, or keep it away forever, but at least for me, so far, it seems to work. This is an easy procedure that anyone can do.
small flat-blade screwdriver
Can of cleaner safe for plastics (I used electronic parts cleaner, but other cleaners may work fine)
Can of silicone spray lubricant
Can of clean, dry compressed air "duster".
1 pair small wire jumpers
Step 1: Remove the solenoid valve from the car.
With the engine cool, open the hood and located the valve. It is tucked inside a metal bracket on the passenger side near the fuse block. It's sort of hidden and a bit hard to see. (Note, my car has a boost cut-out prevention resistor pack under the blue shrink tubing, so your car probably will look a little different than the picture below).
There are two small rubber hoses that need to be removed. I start off by using my needle nose pliers to squeeze the hose clamps loose and slide them down the hoses about 1/2" then I pull the hoses off the valve. No need to mark them, as it is pretty obvious which one goes where. If you find it difficult to get to, you can always remove the two bolts holding the metal bracket to the car. This will give you much easier access, though I don't think it is really necessary.
With the two hoses removed, I then use a small flat-blade screwdriver to push down on the plastic tab while I pull the valve off the bracket, sliding the valve towards the back of the car.
With the valve free of the metal bracket. I use my thumb or the small screwdriver to push down on the tab and pull the electrical connection off of the valve. Time to take it to the bench.
Step 2: Bench Cleaning & Lube
Once on the bench, I slide off the slip-on plastic filter off the valve, and connect the jumper clips to the valve's electrical terminals. Polarity does NOT matter. I also clip one of the jumpers to the battery, with the other one free. Now, as I spray cleaner though all the ports, in all directions, I simultaneously touch the free jumper clip to the other battery terminal, 'popping' the valve OFF and ON WHILE I am spraying. Be sure to use the little plastic spray tube that comes with the cans. The spray cleaner I use is electronic cleaner, mainly since I have it lying around and I know it is safe for plastics and leaves no residue. This technique seems to clean out any grit that may be in the valve.
Once the cleaner dries (it evaporates in just a few seconds), I then repeat this spay/popping technique, but this time as I spray the silicone lubricant in all ports, in all directions. I honestly don't know if this helps or is needed, but I figure it can't hurt.
Finally, I use my can of clean, dry compressed air to blow out the little filter.
Step 3: Reinstall and enjoy!
Once you're done cleaning and lubing the valve, stick the small filter back on the bright metal port of the valve then go out to the car and just plug the electrical cable back in, slide the valve back onto the metal bracket (there's a slot where it slides into), and put the hoses back on and slide the clamps down. With luck, you'll now be BOG FREE.