Stuttering at 4500 on the dot.

[Grimm862]

It stutters quite often at WOT, at 4500 rpms. Its almost a complete loss of power. a miss i guess? What would be causing this? ITS ALWAYS AT 4500. Its got a decently new rotor on it and the plugs are bosch supers.

[jlevie]

Could be a fuel problem (weak pump, pickup screen being plugged by debris in the tank, clogged injectors, etc), a spark problem (bad wires or coil), or a worn AFM. The procedures for testing the fuel system and AFM are in the Bentley manual.