Won't rev over 2500rpms?

[freeandam]

I have a 1990 240sx SE (5 spd) and all of a sudden without rhyme or reason it won't rev over 2500rpms. It sounds like its bouncing off the rev limiter at 2500 rather than keep going. It wouldn't idle either but I fixed that (bottom bolt on TPS broke off allowing TPS to swivel.) I have already changed the M.A.F sensor, spark plugs, Distributor cap and rotor, and fuel filter (all of which badly needed to be changed.) I took off the IAC sensor and cleaned it with carburetor cleaner and I also took the front O2 sensor out to see if the problem was my CAT (it still didnt run right so thats not it.) Myself and a mechanic checked for a Vacuum leak but couldnt find one. I'm really scratching my head on this one and have no clue what could be causing the problem.

[freeandam]

I was just thinking. Of all the parts I replaced, the only one NOT brand new was the M.A.F Sensor. I pulled it from a nissan pathfinder in a junkyard. could that be the problem?

[zachattack_5491]

It's MAF related. Either the sensor itself or the wiring. Bouncing at 2500 is called limp mode.

[asoomal]

Wiggle the MAF connector and see if the problem goes away.

[freeandam]

I found the problem. apparently part of the sensor lies in the housing itself and was damaged. I changed the sensor and the housing (they come together when you order it) and it fixed the problem. I already changed the distributor cap and rotor as well as the spark plugs and the fuel filter and cleaned the injectors. it runs like a champ now!