The VST filter is relatively easy to get to and clean.
0) If you are going to access the VST tank, you really should plan on replacing the gasket, so get one from your local dealer to have on hand. You might be able to re-use the other one, but better to have it if you need it.
1) Before you do anything, depressurize the fuel system by wrapping a shop rag around the schrader valve at the top of the VST tank and "deflating" it using a screwdriver or your fingernail like you would deflate a car tire.
2) Drain the fuel out of the VST tank by removing the drain screw at the bottom of the tank. Remember that the VST tank is where the gas gets mixed with the oil, so don't be alarmed if your gas comes out looking funky.
3) Loosen as many of the screws as you can around the top of the tank, I think there are 9 in total, and 3 or 4 may be blocked.
4) There are three mounting bolts that secure the VST tank to the engine block. If I remember correctly there are also two washers per bolt, one on either side of a rubber spacer, so make sure you don't lose these or forget them.
5) Remove all three bolts and the VST tank should come free. You may have to disconnect one of the wiring harnesses to get enough slack so that you can work on the VST tank.
6) Once the tank is free, remove all 9 of the screws in the top of the tank. The bottom of the tank should drop free.
7) At the bottom of the VST pump, there is a round filter that can be un-twisted. It is part #23 in the diagram below. Make sure to take a good look at how it goes together so that you can re-install it. There is a 'catch' on the filter that gets twisted onto a 'post' to secure it. The filter is the bottom-most plastic piece that has a fine mesh surface that can be cleaned off.
8) Hold the filter up to the sun to see if it is really clogged, and clean it with a shop rag. If you live in the northeast, where we no longer have the sun, use a flashlight or alternative light source. Also check to see if there is any visible debris inside the VST tank and clean it out if needed.
9) Re-install the filter by twisting it back in place.
10) Check the condition of the VST tank gasket, replace if necessary, then put into place.
11) Re-install the 9 screws that hold the top of the tank to the base.
12) Re-install the 3 bolts, don't forget the two sets of washers.
13) You can prime the VST tank by squeezing the fuel primer ball to make sure there is some gas present before starting.
For you guys having surging problems, and haven't done any of the routine maintenance on your engine, there are a couple of other potential culprits.
One is the O2 sensor, which should be tested for correct operation using the test harness, and also visually inspected for carbon buildup and cleaned if necessary. The other are the low-pressure fuel pumps. Your engine will have 2 or 3 of these that should be replaced every couple of years. They are relatively inexpensive. And since you've done this much, its not that much more work to properly adjust the TPS and make sure your oil control rod is properly adjusted.
If I can do it, anyone can.
-- Tom