my Z (z31) wont rev over 4200 (aprox.) under accel. it idle's fine, rev's up to that point fine. when it hits 4200 it seems to bog, and quits acceleration. ive replaced plugs, wires, the cap and rotor are supposed to be new. i replaced the thermostat, housing and gasket, fuel filter, had 2 oil changes in the last 1000 miles ive checked all the grounds, and all the vac lines. everything seems to be in working condition. ive been told that it might be the MAF, but im not too certain. i understand that there is a way to check the wire in the sensor after you turn the car off, and its cleaning itsef. If anyone has some idea's of other stuffi should check it would be appreciated. thanks

 

id suggest replacing the coolant temp sensor. it usually likes to bug out and symptoms show up around 4k rpm.

 

i'll replace that tomorrow morning. thanks. ill let you know if that helsp at all