Bucking stumbling and powerloss KA24de.

[ApisonS-14]

The car is a 1998 240sx. Usually in 1st and 2nd gear at partial throttle it acts as if though im pushing and letting of the accelerator. Or more so jumping forward. I pulled the codes and got an intermittent misfire,map sensor/MAF. So i replaced the MAF.. Problem still there. I replaced the MAP sensor.. problem still there. I unplugged the TPS and drove it.. Problem still there. My IAT sensor is plugged in electronically but it's just hanging due to my intake situation (could this be a problem ) ? Has anyone else had a problem similar to this ? My next move may be to swap ecu's. Thanks

[biggie]

Trying changing spark plugs? Change fuel filter?

[ApisonS-14]

I changed spark plugs. They are correctly gapped. I'll try fuel filter.

[biggie]

Also, miles on the engine/commponets may give an idea. Checked the injectors? One or more may be having issues.

I assume if its idling correct that its not a vaccum leak. But look around for air leaks just in case (have seen rips in intake boots that suck in air under higher rpms but not at idle).