looseing boost???

[Mike Kelty]

 The story  ; its chipped the air box is modded, and the screens have been removed form the maf. the wgs has about 3-4 turns on it
the car usually spikes to 25-29 lbs and settels @ 20-21 and has been doing so for quite some time . Mutual gas seems to be the fastest and most consistant. W/ Amaco -BP it backs off the boost spiking so high a little [not much ] , and still settles at 20.
 
The problem; 4 days ago filled up in the morning W/ Bp car ran great. filled in the afternoon W/ Bp  {Different station} almost  instantly the boost backed off to 17 and then to 15 and sometimes to 10psi .
 
tried and failed cures;
fresh 93 oct from Marathon. nope
swapped maf.    nope
switched wgfv    no go.
no boost leaks
good bpv
 
could there be h2o in the gas. But I run my tank almost dry on every fill up, thus to compere stations. So all the h2o must be out by now if it was there at all. if there was water would it get trapped in the filter. 
 
Other than these thoughts, I'm totally lost with not enough boost to get me off. Please help
 
 
thank you
 
miKe
 
P.S. whats your thuoghts on blow off valves, on these cars.  Just for fun when its time to go to the city. It sounds pretty funny. hehe.

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com