loses power under acceleration

[grendel]

hi, im new to the forums i just picked up a 90 240sx coupe. the car needs a lot of tlc but the biggest problem is if you drive it and press on the gas any more than the tiniest but it will lose all power. it feels like the car died but its still running. im not sure where to start looking. i replaced the sparkplugs, wires, rotor and distributer cap. also my manual window is stuck all the way down, any ideas on how to get it up? but more inportantly the engine problem.

[grendel]

a little more info to help out. the car has 112k miles on it. and i checked codes, it just says 55 meaning its clean. im gonna check the timing tomorrow morning when i get my timing light back but the only other thing i can think is the mafs. any help or suggestions?

[Q45tech]

Code 55 just means that the sensors are putting out a signal [not dead open or shorted] whether the signal voltage is correct requires more diagnosis. Fuel pressure, vacuum, ignition advance are good places to start.