Nissan Repair: nissan pulsar wont rev past 2500, nissan pulsar nx, mass airflow sensor

Question
QUESTION: I have a 88 nissan pulsar nx 1.6L TBI 5speed that will not rev over 2500 rpms.  From idle to 2500 it runs fine but when you hit 2500 it cuts out, acts just like a rev limiter.  The previous owner told me he had the same problem and he would hit the idle air control valve with a hammer and the problem would go away.  The problem has been there since I bought the car and I don't want to buy a $130 part if that's not it.  It seems to me that the IACV would only affect the idle but I could be wrong.  The idle fluctuates between 800-1800rpm.  I have also been told to replace the coolant temp sensor.  None of the advice I have been given comes from experienced mechanics.  Please help.  I can't go over about 48mph with this problem.  Thanks for your time. Matt

ANSWER: Matt,

I would think the mass airflow sensor or the converter would be the problem.  You are correct that the idle air control valve would only be an issue with idle and transition from idle and not at 2500 RPMs.  rockauto.com or courtesynissan.com are both cheap sources for parts.

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QUESTION: Thank you for your response, but this car does not have a mass airflow sensor.  I have also removed the cat converter and tried runing the engine and it does the same thing.  It doesn't chug and sputter like I have experienced in the past with converters being plugged, it cuts out like someone has a toggle switch for the fuel pump and they are flipping it on and of really fast.

ANSWER: Matt,

Check the distributor for the presence of oil on the optical shutter wheel.  Remove the distributor and take the cap, rotor, rotor post and cover off to inspect the shutter wheel and the LED pickup and receiver.  Any oil means a rebuilt distributor is in order.

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QUESTION: Thank you again, the ECU diagnostic info was extreemly helpfull.  I ran the codes and got a 12-air flow meter and a 23-idle switch.  Your response to my first question was air flow meter so I am hoping I'm safe to assume that is causing my problems.  I will get a new one and try it.  What is the idle switch?  I can't find any info or pictures of it, so I don't know what I am looking for or what it's function is?  Could that also be considered the idle air control valve that the previous owner said he would hit?  Thanks again for you time in helping me with this problem, you have been a GREAT help.  I really appreciate it. thx matt

Answer
Matt,

The air meter is a given since you have the code.  The idle switch is the throttle position switch.  It measures where the throttle is and at a given setting the computer knows where idle is.  If the switch is worn out it sends bad data to the computer.  It is on the throttle body opposite the throttle cable side.