Redtop SR20DET only idles with MAF unplugged.

[killmeS13]

I recently swapped a redtop into my 91 240sx hatch. Everything went great until I tried to start it, with everything hooked up, it will start, maybe idle for 1 to 2 seconds and then bog down and bounce around 200rpms and slowly die. When I unplug the MAF the car idles fine but as expected will not rev above 2k rpms. I have checked the maf plug with a multimeter, I get constant 12v on B, ground on C, and .05v on D (all readings froms the harness side). I have swapped the CAS with known working, timing is also good, I used a known working MAF (it is in my coupe that is also SR swapped). I put my ECU in a friends car that is also a redtop in which his car started, ran, and idled fine. I checked for fuel and I'm definitely getting it. I'm running out of ideas here and haven't been able to find anyone with the same issue under the same circumstances, any help insight would be greatly appreciaited

[coupesallday!]

Did you check the idle air control valve?

[S14rebuild]

Did u pull any codes from the ecu?

Stuck idle air control valve?

Vacuum leaks?

Bov stuck open?

[killmeS13]

The car wont idle under these conditions (involving IACV):
-MAF in, IACV in
-MAF in IACV out
It will however idle with:
-MAF out IACV in
-MAF out IACV out

The IACV shows .15v with key in on position and ground shows continuity.

I have checked all vacuum leaks to the best of my ability and have come up empty-handed. BOV is functional, no air noises coming from it, and its brand new.

ECU threw two codes at me
The first time around I got a 55 the second time I got a 12

I'd again like to add, I got that code 12 using a known good MAF that runs my other SR perfectly fine.

[killmeS13]

Okay, so, strange update. Figured I'd try to clear the codes on the ECU and see what I could get it to throw, I got it to throw only 55, then I plugged in everything so I could get an accurate code. So I started it, revved it a little thinking it'd probably try to bog and die right away and it was 100% perfectly fine out of nowhere, it just started running fine, I don't know if messing with the ECU reset it or something but the problem is completely gone. Super weird. Thanks for bouncing things to check around with me though, I appreciate it.