[911 Cab]

Background 1989 911 Carrera, 58,000 miles, bone stock, valves adjusted at 45k and major service at 30k. I have owned the car for 10 years.

During full throttle acceleration between 3,500 and 4,500 RPM car bucks like it is hitting the rev limiter. This only happens occasionally and next minute it is fine.

I have replaced the AFM and problem still exists.

Any ideas?

Thanks