SR stumbling / stalling / backfiring?

[Slo S14]

Hey guys, I have a 95 with a redtop SR basically stock. 3inch o2 outlet, 3inch downpipe and testpipe (stock exhaust minus the rear section which broke off), FMIC, closed mbc, generic air filter, and a walbro 255lph pump. I'm running the stock re-circ valve, and my car is running like crap. Its not missing or anything like that, but it pops between almost every shift. I know a tune will fix the backfiring / popping, but what about the stalling and weak idle? If I'm comming to a stop in gear, and then shift into neutral the car will stall as if I was venting. It will studder when I start off sometimes, and if I give it a rev in neutral the idle will drop way down almost to the point of stalling (which it sometimes does). It normally idles around 900pms, I know there is a fuel issue or an issue with the pump because I can sometimes hear the fuel pump almost loping. There is also a "pssssssssst noise while the pump is priming before I start the car or turn the key to the on position. Could this fuel issue be causing the stalling? I'll mess around with the idle for a bit and see how it does.

*There was a VERY loud pop one night a couple of weeks ago on a shift from 2nd to 3rd, which is when the problem with the idle started. I checked all the piping / hoses / couplers and everything is tight (even checked before and after the mafs). Thanks in advance guys

[fregisr]

besides the idle problem, does it drive normal on cruising speed?

[s13_drftone]

check for leaks from tubing and turbo, fuel can be a huge dilemma

[Slo S14]

Yep, drives perfectly while cruising / accelerating. I'll look for leaks when I get a chance

[fregisr]

get some carb cleaner and spray some on the MAF, and also your tps

[Nismo_Freak]

Get a real BOV, the stock one blows incredibly hard.