Ok here is my problem, yesterday i went to pay a few bills... well i have a tendency with my setup (which is mentioned below) to sit for a moment or two and load up on fuel. Needless to say, i ended up sitting at a traffic light for about 7-10 minutes with an already warm car, took off and car was hesitant, or maybe i should say jumpy, as it acts when it tends to load up. I proceeded to clear it out a bit taching the car out 2nd thru 4th to about 6.5k rpm's, CAR DROVE FINE, hence my reasoning for thinking a fuel load up... well i went in paid my bill, come out and can't start the car. Fuel pump engages, everything comes on fine, whirls over and then BOOM followed by a white smoke coming from my INTAKE! backfire, sounds like it's coming mid exhaust... well i let the car sit a few hours had a buddy come pick me up. Later on i went back, removed plugs (which were BLACK black) manually turned crank to check timing, which is good, getting spark (which is evident), fuel pressure regulator functioning properly... so i decide to retard the timing a bit thru dizzy (thinking it may be bad fuel), to my astonishment, cranks up drive it home.

Now this morning, thinking (from personal experience) possibly a distributor problem, since no clunking sounds or anything of the sort coming from the bottom end, removed valve cover and all valves retainers and such seem fine, placed on new dizzy (used same rotor button and cap though), new plugs (NGK iridium 4's), and REDID the timing (just because it looked about a half notch off (figured that might've been why when i retarded the timing it started no problem, possibly off a tooth or 2)... go to start it up again and same thing happens!!!!

WHAT CAN I DO!?!?!?!

now for my setup, this is all in a 93 civic coupe...
B20b bottom end
R-spec 84mm ITR replica pistons
stock rods and crank
B16a1 HEAD
stock valvetrain
aftermarket cam, stage 1 most likely but resemble GSR cam in markings and lobe
AEM adjustable cam gears (tru-time)
310cc precision injectors
warlboro 255lph fuel pump
ebay fuel pressure regulator
AEM fuel rail
stock b16 intake manifol w/ intake (no filter)
type r 4-1 header replica with 3" coupler connected to straight pipe 2.5" exhaust with 40 series flowmaster muffler (no cat, no resinator)
NGK iridium 4 plugs
NGK 10.5mm wires
95 GSR dizzy

this setup was "street-tuned" on chrome, by a friend... has ran GREAT for last 6 months on 60 lbs thru the fuel pressure regulator... it hasn't seen a dyno and by no means is "tuned"... but is and has been at an acceptable area, if anything running rich with no problems what so ever until the past 2 days of constant rain, moist/cold weather

now with all this being said, new dizzy, plugs, and timing being adjusted, can ANYONE give me an idea of where i should try next, as well as can anyone tell me if the change in moisture of the air will cause this to happen... i know that atmospheric and barometric conditions can effect the preformance of an engine, but this badly? and the compression of my motor is right high at the moment. Maybe a fuel system flush, drop the gas tank, clean it out nicely, run some 93 octane with fuel cleaner and pray for the best? Maybe a problem within the ECU, since no CEL's? Vacuum leak possibility? Tuning is a worry of mine, as i do have hondata s200, it's just that now with this current problem, it won't look as if that'll happen within the next week or so as planned (i'm surely not towing my non running car to a dyno, if that's not the issue). ANY HELP with this problem would be much appreciated

thanks in advance, and sorry for such a long description, just figured it might help
Shawn