My 94 nissan sentra doesn't run smooth over 3000 rpm or if you mash the gas pedal

Fuel pump, clogged fuel filter or clogged air filter

cars are programmed to shift at higher rpm to allow parts to warm up quicker and not stress the engine when its colder - not sure this is what you are asking

it will be either a loose connection /a bad rpm sensor that is causing your problem. It may even be a bad earth wire.

Clean trottle body,Tune up,fuel filter,coils.

likely fuel pump problem..

are you sure that you filled right fuel to your car

u need to replace the clutch, the friction disc is worn out, that is why the hard pedal.

Could be TPS, could be clogged cat converter, could be fouled/worn spark plugs, could be not enough fuel pressure, could be timing, could be......

try replacing the throttle body or throttle position sensor

You most likely need to replace said Mass Air Flow Sensor (MAFS). If you disconnect this sensor, the ECM uses other sensor data to "calculate" fuel delivery. Problem is, this method is not good for real time- meaning that when you hit the gas pedal, the ECM has to calculate the fuel needed and the engine doesn't rev up right, causing more of a driveability issue.

I've replaced quite a few of these sensors. Be sure to buy a new Nissan air filter when you buy the new MAFS. Even if you do the work, Nissan will want to see that should you have a parts warranty (12 months/ 12,000 miles) claim. No air filter replacement (with a Nissan part) = no warranty coverage.

This is not the most accurate test to use to check the operation of a MAFS, but it usually gives you an idea if you're in the right area- idle smooths when disconnected usually means you are in the right area.


Hope this is helpful!!


Nissan Scope Technician- 10+ years experience in Nissan dealership.