i have a saturm sl2 when ever my rpm goes over to 4 my engine start cutting down and shaking what do u think the problem is??
(i changed to spark plugs and cables,air filter)

On my 96 the RPM rarely got anywhere near the 4 mark. does it do this if you rev it when parked? If so maybe fuel filter?

I beleive it's the fuel cutoff at 4k RPMs Parked or neutral. But I can hit 5 and 6k RPM when driving in my 96sl1... Manual. These engines are designed to be driven at high RPMs.

exactly. either/or the governor. the governor activates around 4 to 4.5k in park or neutral, not allowing the engine to rev high enough for, oh say, a burnout with mom's car