Nissan Repair: 1997 nissan altima, mass airflow sensor, nissan altima

Question
I've been having problems with my 97 altima. First the car was hesitating a little when i would take off and the check engine light came on. So i changed the plugs, wires, cap, and rotor. But it seemed to get worse after that. The car was hesitating alot more when taking off and idling really rough. Then I took the car to a shop that my uncle works at. He said it seemed like it was a bad fuel injector. He tested the valve pressure and said it was good and that the plugs were all firing. After one defective remanufactured injector, I bought a new injector and replaced it. The car got alot better, I would say about 70% or so, but is still idling rough and hesitating when taking off. But it isn't near as bad as it was before. Need some help on my next move. Thanks alot

Answer
Josh,

A couple of things here to look at are the injectors.  Check them all and make sure they are operating properly.  Do an ohm check and see if they all read the same.

Second, the mass airflow sensor could be defective and/or the hose that goes between it and the throttle body could be cracked or the clamps could be loose.  Any unmetered air entering the system can cause the rough idle and hesitation.  Also, be really sure that the PCV valve is in good working order.  If it is stuck it could cause the problem too.  But, check the injectors first.