Odd loss of power only from a stop.

[Chiffchiff]

Ok, I have an 89' 240 with a newer s13 ka24de installed. I bought the car a few weeks ago with the swap done (it also was converted from auto) When the car is warmed up and I go WOT from a stop it feels like its only at 1/2 to 3/4 throttle and the intake is quiter than normal. If I cruise along for about 3-5 minutes and then downshift and go WOT it feels like it should and has plenty of power. This happens everytime I come to a stop. If I just slow down to a couple miles an hour (like to take a turn onto another street) and go WOT in 1st it has power still. I've done a full tune up (plugs, wires, cap, rotor, fuel filter, compression test, and checked the timing) and still the same problem. I checked the codes on the ecu and it was showing a code 12 (Mass airflow sensor circuit) So I found a used MAF sensor and put it in and the code is now gone but the problem still present. There is no other hesitation, sputtering, bucking, etc. It just doesn't accelerate at all from a dead stop. I've even tried holding the throttle while stopped and keeping it revved about 2k rpms. Still no dice.

Is there anything that having to do with the auto to manual swap that could cause this? It also has an Injen intake and the line for the EGR back to the intake has been capped off with a breather filter.

I'm gonna keep plugging away and checking every electrical component I can till I find something (I have the FSM and all the diagnostic/troubleshooting procedures) I'm just curious if anyone has run into this problem.Edit/Delete Message