Weird behavior of engine and rpm when car goes higher in revs, Porsche 911 2.7.

[Pascal]

Hi Johnny,

I bought a CDI+ system (3 pin) from you several years ago along with the coil from classic parts.
Now what I experience lately is that the car acts weird when I go higher in revs (+4000 rpm) it holds back and my tachometer needle suddenly goes to 5000 or 6000 rpm.
I have already replaced the distrubutor cap and rotor, timing is ok. It is also only when I go above 4000 rpm.
Do you have any idea what could be causing this?
 

thanks

pascal.

[Jonny Retrofit]

Sounds like the coil but I would also check the points gap is within spec.