Tachometer is very spastic from time to time

I have noticed that when driving my 2000 3.1L Alero, that sometimes the tachometer jumps all over the place and that the acceleration is not the best. This only occurs for a matter of 15-30 seconds and then the car accelerates just fine. When the tachometer is acting possessed I notice that my car's acceleration is poor and it seems like my car's engine is experiencing some hesitation. Any suggestions on what the potential problem may be and possible solutions?

Welcome to AF.

You have a typo on your engine size. It is a 3.4L.

Sounds like an undetected misfire cause by a secondary ignition issue. Spark plugs, ignition wires, or possibly a coil pack or ICM - Ignition Control Module..

When was the last basic tune-up including fuel filter? Do you ever get a SES/CEL light?