engine hesitating at 3000rpm

[200sx-v8]

I'm having some troble with my engine at 3000 rpm. It hesitates, and it seems as it cuts on some cylinders or something. It's only under light load cruising I get this problem.

The afr looks very good, and there is not anything starnge with the timing at this rpm.

Any ideas?

 

[V8superlux]

Sounds like it could be a dud plug lead or water down the spark plug tube (if you have washed your engine lately. Pull the leads out and check there resistance, the should be between 1 and 7k ohms (short ones closer to 1 and longer ones closer to 7) but if you have a bad one it will most often be open circuit.
May be worth fitting new plugs while its all apart most common way to damage a lead is while changing plug.