The car won't rev up. It idles fine but under throttle won't go past 2000 rpm.

Is your check engine light on? Suspect catalytic converter. These can get pricey, so having it scanned and diagnosed is key. Check out the certified shops in your area at this link below. http://repairpal.com/infiniti-within-10-miles-of-hickory-north-carolina-28601

IF you have the equipment and ability to use accurately..... Fuel PRESSURE with an analog gauge??#Lb. and using a vacuum gauge , manifold vacuum at idle when cold , then when at 2000 rpm , and at idle when warmed up and then at 2000rpm?