I'm having issues w/1JZ spooling up.
 

Just recently I replaced my turbos with a set from another motor with around 45k on it. They had no shaft play and are in great condition. I do plan to go single soon but with a baby on the way it's just not in my budget right now. So.... I need to figure out what's going on with my car for now.

So here's what happens - "sometimes" when I go to spool up, it wants to act as if it's trying to fuel cut and it spits and sputters. Now this only happens sometimes, hence the quotes. Somedays I can go all day and not have any issues at all and it spools fine and runs strong. Somedays it will go to spool then hesitate (as if fuel cutting) and then take off.
Anyone have any ideas what this could be? I'm working on getting another DP and having a O2 bung welded in for a wideband so that I can better tune the S-AFC very soon. Could this have anything to do with a bad map sensor or anything like that?
Here's my setup - 1JZGTE, stock 12-13 lbs boost, Apex'i S-AFC, Apex'i Manual Boost Controller, Walbro FP, FMIC, etc.
Any help and guidance would be great.

check spark plugs

plugs shouldn't be at start of boost, but eh :-\
edit: took out 2nd part after reading end of ur post
since somtimes, is this only after a wash or seeing water?(vj seems to like the "map got wet" answer for sputtering :))

I had a similar problem in my 240 and it was a timing issue.

No water or any dampness involved. The reason I was wondering about the map sensor is b/c it seems like I read somewhere that someone else was having a similar issue and it was b/c their map sensor was bad or something. It's been a while and I couldn't find that again.
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the basic job for the map sensor is its a "LOAD SENSOR"

so your trying to spool up - your altering the current load on the engine.
stands to reason & would be the 1st thing to check.

the other is the ignition, a combustion mixture under pressure takes more
voltage to ignite than n/a. you may have a bad spark plug(s) as mentioned or
a bad coil pack (s). when your spooling it up the increased cylinder pressure
maybe blowing the flame out causing a misfire. coil packs are also susceptible
to moisture problems (arching) just like plug wires.

FInally got a chance to check out that map sensor b/c I have a spare now. As I went to pull off the plug it broke into a bunch of little pieces and I figure that might have had something to do with it. Luckily my buddies at Fastech had an old MR2 wiring harness laying around that I got a plug off of. HEHE. It got a little late so I'll try this again on Wednesday.