89' 240sx SOHC hesitation

[hbrown]

I'm having trouble with a nasty stumbling hesitation when the engine is loaded at low RPM- once it gets up to about 2500RPM, it cleans up and pulls like normal. I'm thinking MAF sensor, or O2 sensor. Plugs and wires are good, drop in K&N filter is clean, I have cleaned the throttle body, fuel pump and filter are new, idle is normal. The stumbling is worse when the engine is at normal operating temperature- when cold, it runs much better. I have been driving it all this week like this- for lack of a chance to really get into it and try to trobleshoot it. It seems to be getting worse- in a few days I won't be able to drive if it continues to get worse. Anyone have any feedback?Thanks,

[Nitrus0nous]

try cleaning the mafs. mine was way oily, i guess from the oil for my air filter. just sprayed some electrical cleaner in the 2 holes, took it apart carefully and cleaned the 2 sensors under the black box, and now it runs like a champ.