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my 93 240sx 5spd manual idles great but acts sluggish when trying to rev. the car will run great to about 1/8 to 1/4 throttle but as soon as i give it more it actually loses power. it also doesnt want to rev much past 4000rpm. i just bought the car and the previous owner just got done replacing
fuel pump and filter
maf sensor
injectors

no codes are known to be active but will check for sure in the next few days

if anyone has any ideas or first hand knowledge it would be greatly appreciated. i have done a search but everything i find doesnt quite sound like what im experienciing.
i also have a 90 240sx manual that is twice as fast, stock and has twice as many miles on it.

 

sounds like your MAF. Try disconnecting the battery for a few hours, (this will rest your ECU) then reconnect the battery and the ECU should recognize the MAF. After reconnecting the battery, drive it like you stoled it for a few miles and your ECU will reset itself for higher performance.

 

ill try that tomorrow, i have also noticed that the car doesnt ever want to warm up is this common during the winter in these cars

 

well found part of my problem. it was a bad resistor wired into the coolant sensor.
a stupid "performance chip" car is running better but still feels like its holding back above 5000rpm. i dont expect it to take off like vtec but shouldnt it still pull fairly strong to redline? im still a newb to 240's. my other car is an rsx type-s

 

so whats that all your problem...cuz i am having the same problem

 

well it ended up being a few things. first there was the chip but the connections on the plug of the coolant sensor were also coroded and not getting a good connection, i also replaced the thermostat which fixed the warm up problem. i also found some loose wires in the plug of the maf sensor, and finally i found on my injen intake the front mount had broke creating an air leak behind the maf under acceleration. u might try the same things good luck finding your problem.